9 June 2026 | Jennifer Parker *Originally published in The Australian Defence Supplement on 2 June 2026 Image: The first Speartooth LUUV is handed over to the US Navy at C2 Robotics’ Melbourne site. From left, RAN Navy’s Directorate of Maritime Integrated Capabilities Captain Tony Miskelly, C2 Robotics chief executive Troy Duggan, and US defence attache in Canberra, Captain Josh Fagan, USN. Picture: C2 Robotics Australia is critically dependent on infrastructure lying on the ­seabed. More than 95 per cent of our international data traffic travels through subsea cables, alongside the pipelines and energy infrastructure that underpin the economy. As the maritime domain becomes increasingly contested, the battle beneath the oceans is intensifying. Chinese naval deployments around Australia are reminders that control of our ­surrounding seas can no longer be assumed, and we should apply the same assumption to the underwater domain. Undersea cables, seabed infrastructure and the systems used to monitor and protect them are now part of strategic competition. That growing vulnerability helps explain Australia’s increasing investment in undersea warfare capabilities, including systems such as Ghost Shark and Speartooth. While significant gaps remain in areas such as hydrography and mine warfare, investments in capabilities including AUKUS, the Hunter-class frigate’s towed array sonar, the Bluebottle uncrewed surface vessels with towed array sonars, and uncrewed underwater vehicles should provide Australia with the greatest underwater situational awareness capability it has ever possessed. What happens in the underwater domain, and our ability to respond to developments there, is understandably shrouded in secrecy. But in April, British Defence Secretary John Healey provided a rare public glimpse into this contest when he de­classified a Russian operation inside the United Kingdom’s Exclusive Economic Zone. The operation involved a Russian Akula nuclear-powered submarine and two specialist vessels from Moscow’s Main Directorate for Deep Sea Research, which Healey said are designed to survey underwater infrastructure in peacetime and sabotage it in conflict. The UK has every reason to be concerned following a series of attacks on undersea cables and pipelines in the Baltic Sea. But the capability to interfere with subsea cables, pipelines and broader seabed infrastructure is rapidly expanding. China is investing heavily in undersea capabilities, from sensors and uncrewed underwater vehicles to increasingly sophisticated submarines. In 2025, considerable attention was given to reports that Chinese researchers had developed a deep-sea cable cutter capable of severing cables at depths of up to 4000m. Chinese-flagged vessels, and vessels crewed by Chinese nationals, have been suspected of interfering with several subsea cables servicing Taiwan. The growing accessibility of uncrewed underwater vehicles (UUV) also means state and non-state actors increasingly have the ability to surveil and interfere with critical underwater infrastructure. Key to underwater domain awareness is understanding where your vulnerabilities lie and maintaining strong maritime domain awareness above the surface. Many recent incidents involving undersea infrastructure have not involved submarines at all, but ­surface vessels dragging anchors across cables and pipelines. Monitoring one of the world’s largest maritime domains is an immense challenge, made harder by Australia’s fragmented maritime security architecture spread across multiple agencies and without a dedicated coastguard. Amid this growing competition, Australia does appear to be leaning more heavily into undersea warfare capabilities. In 2024, the government projected that undersea warfare would account for 17 per cent of the Defence Integrated Investment Program (IIP) over the decade. In 2026, that figure increased to 23 per cent, the single largest proportional investment area. Much of this investment is driven by Australia’s nuclear-powered submarine program, although the full scope of Australia’s undersea capabilities likely remains classified. Still, there are some public ­indicators. The government has announced a $1.7bn investment in the Ghost Shark extra-large autonomous underwater vehicle, and an undisclosed investment in the smaller, much more affordable Speartooth large uncrewed underwater vehicle (LUUV) which is optimised for seabed warfare and agile undersea operations, reaching areas Ghost Shark cannot. Manufacturers C2 Robotics last month also delivered the first of a batch of Speartooth LUUVs to the US Navy. And late last year, the US Navy ordered a variant of Ghost Shark to demonstrate delivery of large payloads across extended ranges underwater. The full capabilities of Ghost Shark and Speartooth remain unclear publicly, but Defence has promoted their potential roles in intelligence, surveillance, reconnaissance, logistics and strike. Taken together, these capabilities should significantly strengthen Australia’s broader undersea warfare posture. This investment is also supported by the 2023 acquisition of ADV Guidance, a converted civilian vessel intended to support undersea operations. In any future regional conflict, and potentially well short of conflict, Australia’s critical undersea infrastructure will be targeted. Protecting it requires Australia to understand activity both above and below the sea. That demands a genuinely integrated maritime security architecture, clear responsibilities across government, and the capability to detect and respond to threats. Australia’s maritime security system remains fragmented and, at least publicly, responsibilities for protecting subsea infrastructure are far from clear. But from a capability perspective, Australia does appear to be leaning into ­elements of the challenge through investments in Hunter-class frigates, uncrewed underwater vehicles and broader undersea warfare capabilities. Australia is finally beginning to invest seriously in understanding and operating in the underwater battlespace. Given the nation’s dependence on critical seabed infrastructure, that investment is long overdue.

5 June 2026 | Jennifer Parker *Originally published in the Conversation on 5 June 2026 Image: The Conversation (Virginia-class fast attack submarine USS Minnesota, pictured here in Perth, is a Block II vessel.Colin Murty/AAP) Following the recent announcement that Australia would acquire three submarines already in US service rather than two used submarines and one new one, AUKUS has again dominated headlines. AUKUS is a defence capability agreement between the United States, the United Kingdom and Australia. Since it was announced in 2021, it’s rarely been out of the news. But how much of what you have heard is true? As a former Navy officer specialising in anti-submarine warfare, I am frequently asked the same questions about AUKUS. While I can’t address everything in one article, here are the details behind some of the most common claims. Why is Australia buying used submarines? Australia has Collins class submarines that entered service between 1996 and 2003. Work should already be underway to replace them, but decades of delays and underfunding have left us with an ageing fleet. Though the Collins class submarines will each go through a multi-year maintenance period extending their life, they won’t last long enough. They will need to be decommissioned before Australia can co-design, build and produce submarines here under AUKUS. A stopgap solution is required. The purchase of three Virginia class submarines in 2032, 2035 and 2038 will provide this, and also give Australia the ability to start operating nuclear-powered submarines. Think of it as a “crawl, walk, run” approach. The Virginias are the walk phase before we start building our own nuclear-powered submarines. Acquiring submarines already in service reduces risk and complexity, avoids the challenges of introducing a new submarine, and removes the need for initial certification trials. Is Australia getting a less capable submarine? Not in any meaningful sense, though the third Virginia will be an older version than planned, so its sensors will probably be slightly less capable. Australia will now receive three Block IV Virginia class submarines. These remain among the most capable attack submarines in the world. They carry more than 20 torpedoes and 12 Tomahawk land strike missiles. Much of the commentary this week has suggested Australia has lost additional missile capacity because the submarines we’re receiving won’t have the “Virginia Payload Module” – a new hull section that allows the submarines to carry more missiles. But that commentary is incorrect. The submarine Australia was expected to receive in 2038 was never intended to have that capability. In conflict, Australia would predominantly use these submarines in an anti-submarine and anti-ship role. Land strike missiles are not used for this and so the extra capacity isn’t essential. It’s also capability the US has said it is not willing to provide. The main difference is the third submarine will have fewer years of life remaining than a new boat. A Virginia class submarine off the production line would normally have a 33-year life. At Senate estimates this week, the Australian Submarine Agency said each boat will have more than 20 years of life remaining when we receive them. Claims these submarines would only have eight years of life do not withstand scrutiny. The kind of submarines Australia will receive only started entering service in 2020. Are we paying $368 billion for three used submarines? The figure most often quoted for AUKUS is $368 billion. While technically correct, this figure covers costs through to 2055 including infrastructure, workforce and maintenance costs over 31 years, plus the purchase of Virginia class submarines to Australia and building our own submarines. Of the total, about $244 billion is the projected cost, while the remaining $122.9 billion is a 50% contingency on top. This is money set aside to cover risks, cost growth and unforeseen problems. Most defence projects carry 5–10% contingency. The Department of Defence’s 2026 Integrated Investment Program states nuclear-powered submarines will cost between $71 billion and $96 billion over the next decade. Against projected defence funding of about $887 billion over the same period, this equates to around 8–11% of defence spending. Can the US build enough submarines for Australia? This is one of the most legitimate points of debate in the discussion. The US reduced its production rate of submarines after the Cold War. Since 2011 it has set a goal of increasing its build rate to two submarines a year. From 2016–19 it averaged 1.9 boats a year. According to the US Congressional Research report on Virginia class submarines, this build rate dropped off due to workforce issues during COVID and challenges associated with moving to the build of the new Block V submarine, which is 2,000 tonnes larger than the Block IV Virginia. The US is investing billions of dollars into its submarine industrial base to address this issue. In May, Chief of Naval Operations Admiral Daryl Caudle told Congress he expects Virginia production to reach two boats per year in around 2032. He previously said the US will need to get to a 2.3 production rate to get to its 2054 goal, including the sale of three Virginias to Australia. The US is presently building 1.3 a year. The US submarine industrial base challenges are real, and will take significant effort to address. Has the US said it will not sell submarines to Australia if it doesn’t get there? No. Is AUKUS risky? Yes. AUKUS is the most complex defence project in Australian history. There are risks in the US and UK industrial bases, workforce growth, infrastructure and funding. Anyone claiming otherwise is not engaging with reality. But much has been achieved in less than five years. Australia has established a submarine base near Perth, embedded personnel in US and UK submarine programs, commenced major infrastructure works, trained hundreds of personnel, and secured US congressional approval for the submarine transfers. At the recent AUKUS Defence Ministers’ Meeting, all three countries stated the program remained on track. Based on the evidence available today, I agree. This is a multi-decade program. There will be changes along the way. Not every adjustment is evidence of failure. What happens if Australia abandons AUKUS? Australia cannot simply walk away from AUKUS and pick another submarine off the shelf. Any alternative would require a new acquisition process, a new agreement and years of negotiation. There is also no obvious replacement. France’s nuclear-powered submarines, for example, are built through a single shipyard and can take more than a decade to complete. If Australia was to abandon a second submarine program in little more than a decade, this time with our closest ally, it would be hard to imagine another country lining up to partner with Australia on a future submarine project. After cancelling the French submarine program and significantly reducing other naval programs, our reputation for delivering in this area is already under pressure. AUKUS should continue to be scrutinised. But that scrutiny should be anchored in facts. Any proposal to abandon it must also explain what replaces it and how Australia avoids a submarine capability gap. Having spoken with officials in our partner nations, the concern raised most often is not the US or UK industrial base. It is Australian political will. As a nation, we should be mindful of that and measured in our debate.

4 June 2026 | Jennifer Parker *Originally published in the Lowy Institute's The Interpreter on 4 June 2026 The announcement this week changed the mix of submarines Australia will receive – it did not change the program’s purpose, or its prospects. Image: United States Navy Virginia Class submarine USS Mississippi arrives at Fleet Base West, Rockingham, Western Australia for a routine port visit. Defence Images. Much of the reaction to this week’s AUKUS announcement that Australia will acquire three in-service Virginia-class submarines and forgo buying a new US-built boat has missed the point. While some have portrayed the decision as a fundamental change to the deal, in reality, it is a relatively minor adjustment to a program that will run for more than 30 years and one that actually reduces risk for Australia. The practical effect is that all three Virginia-class submarines Australia acquires in the 2030s will be of the same configuration. That matters. Commonality is a core principle in capability acquisition. Operating three of the same submarines simplifies workforce, training, maintenance and sustainment requirements. The downside is that an in-service submarine has less life remaining than a newly built boat. But that was already true of the first two submarines Australia was due to receive. The operational benefits are real. The boats will have common systems, support requirements and training pipelines. It also reduces pressure on the United States industrial base by removing the need to build a separate submarine for Australia. But it does not change the purpose of AUKUS. Debating whether the third submarine is new or already in service misses the more important question. The objective of AUKUS has never been to acquire three Virginia-class submarines. The objective has always been to establish an Australian nuclear-powered submarine capability and industrial base. That was the goal when AUKUS was announced in 2021 and it remains the goal today. The Virginia-class submarines were always intended as a bridging capability, ensuring Australia built a submarine force while developing the workforce, infrastructure and industrial capacity needed for its own nuclear-powered submarines. The Virginia-class subs also provide a pathway to develop the skills and experience required before the arrival of the first Australian-built boat. This week’s announcement does not change that trajectory. If anything, it reduces some of the risk along the way. Debating whether the third submarine is new or already in service misses the more important question. Is Australia progressing towards building a local nuclear-powered submarine capability? The answer is yes. For an island nation with one of the world’s largest maritime domains and an economy dependent on maritime trade, submarines are essential to maintaining the capability to protect its interests. There will always be arguments for and against nuclear-powered submarines. Just as there are arguments about tanks, frigates, fighter aircraft or the structure of Defence itself. Debate is healthy. An informed public debate is essential to the country. For all the claims of crisis – including in launching a self-appointed inquiry. into Australia’s submarine capability – the program has survived political change in all three countries and reviews in both the United States and United Kingdom. The plan for the three-phase pathway was agreed by all three countries within 18 months of the announcement. Australia has embedded hundreds of personnel in US and UK submarine programs, begun maintenance on allied nuclear-powered submarines and is preparing HMAS Stirling to support Submarine Rotational Force-West next year. Discussions with the International Atomic Energy Agency are progressing and the design for the shipyard that will build the submarines in South Australia is in progress. In truth, much has been achieved in the nearly five years since AUKUS was announced. Risks remain. No major defence project is risk free, and AUKUS is the most complex capability program in recent Australian defence history. But these risks should be considered in context and grounded in fact. Challenges in the US and UK submarine industrial bases, workforce generation, infrastructure and funding are real, but they are known and being actively managed. These risks require management, not abandonment. If Australia were to abandon a submarine program that remains on track, it would almost certainly forgo a credible submarine capability for a decade or more, at a critical time for the nation’s security. Walking away from a second submarine program in little more than a decade, this time involving the country’s closest ally, would also further damage Australia’s reputation as a defence partner. After abandoning the French Attack-class program and significantly reducing the planned production runs of the Hunter-class frigates and Arafura-class offshore patrol vessels, there would be limited confidence among major submarine builders that Australia could be relied upon to see such projects through. Australia should continue to scrutinise AUKUS, challenge assumptions and test alternatives against the facts. But the reality is that AUKUS remains on track.

26 May 2026 | Jennifer Parker *Originally published in The Australian on 26 May 26 Image: 4.5 tons of Wold War II High Explosive is destroyed just off the coast of Bougainville during Operation RENDER SAFE 14. Defence Images. Australia is an island nation with one of the world’s largest maritime domains, and its prosperity and ­security depends on seaborne trade, including fuel, fertiliser and pharmaceuticals. Yet as Australia invests heavily in nuclear-powered submarines and an expanded surface fleet in the 2030s, a critical vulnerability remains: Australia has little real capacity to detect and clear sea mines. Sea mines are the simplest way to shut down a port, a chokepoint or a coastal trade route. They can be laid at scale by dedicated vessels, but just as easily deployed by submarines, fishing boats or other vessels of opportunity and, increasingly, uncrewed systems. As the Strait of Hormuz shows, even the suggestion of mines is enough to deter traffic. Iran’s warnings alone have kept most ships away, with the few transiting vessels steering clear of the traffic separation scheme, which Iran has declared mined, and hugging the coasts. Australia’s coastal waters were mined during both world wars, first by a German raider and later by German raiders and Japanese submarines. The Royal Australian Navy also laid defensive mines to protect key ports and restrict submarine access. After World War II, the Royal Australian Navy spent years clearing more than 1800 mines. In 1947, HMAS Warrnambool was lost during these operations after striking a mine, with four sailors killed. Australia’s geography makes it particularly vulnerable. Its large ­island mass and dispersed ports mean mining is a simple and effective way to shut down access. The People’s Liberation Army – Navy is assessed to hold a vast inventory of sea mines, likely in the tens of thousands. In any major Indo-Pacific conflict, Australian ports and key chokepoints such as the Torres Strait should be expected to be mined. Mines would stop our ports and coastal trade, and threaten the operation of our naval forces, ­including nuclear-powered submarines. Mines near HMAS Stirling would immediately halt operations at our only submarine base. Given Australia’s experience during both world wars, and China’s vast sea mine inventory, mine clearance should be a priority. It is not treated as one. Australia’s capability is in a parlous state, having been neglected for decades. This is not new. In 1989, the Joint Standing Committee on Foreign Affairs examined the threat mining posed to Australia and the capability required to respond. It prompted a reinvigoration of mine warfare, including reorganisation and, critically, acquisition. The committee was clear that “the development of a capable mine countermeasures force must be one of the highest priorities for the ADF.” Yet in 2026, while our geography and maritime dependence remain unchanged, the threat has grown. We have no strategic warning time, we face our most ­dangerous circumstances, and our mine warfare capability is marginal at best. Of the six minehunters commissioned in the 1990s and early 2000s, only two remain. Both are over 20 years old, heavily used and nearing decommissioning. Their planned replacements and the deployable mine warfare capability under SEA 1905 were cancelled in the 2025 Integrated Investment Program, most likely due to budget pressures. The result is stark. In 2026, Australia is left with two ageing minehunters and a small, Sydney-based team operating limited, largely experimental systems, including reportedly fewer than 20 uncrewed underwater vehicles and a handful of mine neutralisation systems. Mine warfare received little ­attention in the 2024 Integrated Investment Program, and the cancellation of future capability has been met with claims it will be solved by autonomy. Uncrewed systems will shape parts of mine warfare, but without a clear plan or platforms to deploy them from, that promise is hollow. Beyond port clearance, these systems still need to operate from a vessel, and the last suitable platforms are nearing decommissioning. “Vessels of opportunity” lack the hardening and signature management required to operate in or near a minefield. Advances in autonomy reduce risk, but do not remove the need for vessels. The Royal Australian Navy needs deployable mine clearance capabilities that make use of ­advances in uncrewed systems, but it also needs dedicated vessels to operate them from. Yet the latest Integrated Investment Program expands its discussion of mine warfare without allocating funding to a capability identified as a top priority more than three decades ago. The point is simple. ­Nuclear-powered submarines are of little use if the waters outside their ports are mined. Beyond capability, Australia needs a concept of operations, as recognised in the 1989 Senate inquiry. Mine warfare must be distributed and responsive. It is of little use concentrating capability in Sydney if Port Hedland is mined. Australia needs deployable mine warfare teams and key capabilities positioned across both coasts. This is well suited to a model supported and augmented by a reinvigorated Naval Reserve. Australia’s ports, coastal trade routes and Pacific partners are vulnerable to mine warfare. As in the past, in any regional conflict Australian waters should be expected to be mined. Despite having no strategic warning time and facing our most dangerous circumstances since World War II, Australia has little more than a token capability to respond. That must change, and quickly.

22 May 2026 | Jennifer Parker & Dr Troy-Lee Brown *Originally published on 22 May by the Perth US Asia Centre The Iran war is again exposing a reality Australia has long overlooked: the Indian Ocean sits at the centre of the nation’s economic and strategic security. Image: United States forces prepare to board an oil tanker in the Indian Ocean in early February 2026 after the vessel violated a U.S. embargo of sanctioned ships in the Caribbean. U.S. DEPARTMENT OF WAR Key takeaways Australia’s economic and national security are deeply tied to the Indian Ocean. Western Australia’s ports, energy infrastructure and subsea cables are critical national assets, but remain lightly protected. Competition in the Indian Ocean is growing through naval presence, China’s infrastructure investment across the region, and undersea activity. Australia’s growing focus on the Indian Ocean will require a clearer strategy and stronger maritime posture. The Iran war is again exposing a reality Australia has long overlooked: the Indian Ocean sits at the centre of the nation’s economic and strategic security. For decades, Australian strategy has been dominated by a Pacific outlook. Much of the nation’s defence infrastructure, force posture and strategic thinking developed along the east coast and looked towards the Pacific. Yet Australia’s security and prosperity have always depended on the Indian Ocean. The region carries critical sea lines of communication linking Australia to fuel, trade, and global markets. Much of the nation’s prosperity is tied to Western Australian ports, from Port Hedland, Australia’s largest bulk export port, to Fremantle, a critical gateway for container trade and maritime logistics. Together with major energy export hubs such as Karratha, these ports underpin not only Australia’s economy, but increasingly its national security. Much of the nation’s prosperity is tied to Western Australian ports… these ports underpin not only Australia’s economy, but increasingly its national security. The Indian Ocean: An increasingly contested region The Indian Ocean is no longer a secondary theatre. China has steadily expanded its presence across the region through port investments, dual-use infrastructure, and growing undersea surveying activity. At the same time, the Iran war has again shown how quickly instability in the Indian Ocean can disrupt shipping, energy supplies, and maritime trade far beyond the Middle East. The sinking of the Iranian warship Dena by a US submarine off Sri Lanka in March this year, reportedly along key maritime routes to China, was a visceral reminder that the Indian Ocean can no longer be viewed as strategically benign. Persistent vulnerabilities in the Indian Ocean Australia is increasing its presence, capability and partnerships in the Indian Ocean. AUKUS, Australia’s rapidly expanding defence relationship with India, and its growing engagement across Indian Ocean states all reflect this shift. Australia’s defence relationship with India has shifted significantly over the past decade, while Australia’s Defence Cooperation Program has also expanded into the Indian Ocean, including the delivery of an Australian-funded Guardian class patrol boat to the Maldives earlier this year. These developments reflect a growing recognition that Australia’s strategic interests extend well into the Indian Ocean. Australia has pivoted towards the Indian Ocean before, from the establishment of HMAS Stirling in 1978 to the formalisation of its two-ocean strategy in the 1987 Defence White Paper. Yet the importance of the Indian Ocean continues to slip from Australia’s broader strategic debate. While Australia is increasingly focused on its dependence on, and access to, the Indian Ocean, significant vulnerabilities remain. Australia still has limited capacity to protect critical ports and infrastructure in the northwest, particularly in areas such as mine warfare, port protection, and maritime security operations. Maritime competition and domain awareness Strategic competition is reshaping the ways in which power is exercised in the Indian Ocean. From a more persistent naval presence to expanding economic and security relationships, regional dynamics are shifting rapidly. China, in particular, has expanded its investment and influence across Indian Ocean littoral and island states as it seeks to secure access to critical maritime trade routes. Over the past decade, an increase in Chinese ‘scientific research’ vessels has coincided with a greater presence of PLAN (People’s Liberation Army Navy) surface and potentially subsurface vessels. These changing dynamics underline the growing importance of achieving a clearer picture of what is going on in the Indian Ocean through improved maritime and undersea domain awareness. Subsea infrastructure and maritime vulnerability The strategic significance of the Indian Ocean is not just the maritime trade routes linking Europe, the Middle East, Asia, and Oceania. It also lies in the dense network of undersea fibre-optic cables that keep our economy online and powered. Perth has emerged as Australia’s major subsea cable hub. At the same time, systems such as the North West Cable System linking Darwin and Port Hedland underpin connectivity for Australia’s critical resources and energy sectors. These vital connectivity links sit alongside key ports in northwest Western Australia that are critical to the economy, yet remain lightly protected, with few maritime assets permanently based in the region. This also raises a broader question about how much visibility Australia really has across its western maritime approaches and beneath the sea in the Indian Ocean. We have already seen the impact of contested maritime domains and the growing accessibility of technologies capable of threatening shipping and maritime infrastructure. From the Black Sea to the Middle East, low-cost mines and uncrewed systems have shown that you do not need a large navy to cause significant disruption. Attacks on shipping, or even the suggestion of maritime threats, can send insurance premiums soaring, reroute shipping and disrupt global trade. The consequences for Australia would be significant if uncrewed underwater vehicles targeted the North West Cable System or if it was suggested that sea mines had been deployed near Port Hedland. Australia’s Indian Ocean shipbuilding and sustainment hub A significant increase in investment in critical Defence-related infrastructure has positioned Western Australia to play a greater strategic role, especially in the maritime domain. Infrastructure on HMAS Stirling was already undergoing extensive upgrades prior to the AUKUS announcement. In addition, the Australian Maritime Complex at Henderson is also being transformed, reflecting the growth of the defence industry – now set to become WA’s second largest industry after resources. In 2025, Austal and the Commonwealth signed a 15-year Strategic Shipbuilding Agreement that will see the long-time Henderson-based shipbuilder construct general purpose Mogami frigates for Navy and Landing Craft Medium and Landing Craft Heavy for Army. The uplift in maritime infrastructure positions Perth to play a broader role as Australia’s Indian Ocean gateway for sustainment, logistics, and the development of surface and undersea capabilities across the region. The uplift in maritime infrastructure positions Perth to play a broader role as Australia’s Indian Ocean gateway for sustainment, logistics, and the development of surface and undersea capabilities across the region. Australia’s incomplete Indian Ocean pivot In many ways, Australia’s Indian Ocean pivot is only half complete. Nearly 40 years after the two-ocean navy strategy was introduced, it is time to think more seriously about what an Indian Ocean strategy requires. Australia has built a far larger footprint in the west through infrastructure, capability investment, and partnerships. But significant gaps remain. Northwest Western Australia is critical to the nation’s economy, yet still has limited protection and domain awareness. As the Indian Ocean becomes more contested, Australia needs a clearer strategy for the region and a maritime posture that reflects the region’s growing strategic importance.

9 May 2026 | Jennifer Parker *Originally published with Channel News Asia on 9 May 2026. Access original publication here The abrupt “pause” of Project Freedom after two days undermines confidence in the United States’ ability to secure the critical waterway, says defence professor and navy veteran Jennifer Parker. Image: Guided-missile destroyer USS Rafael Peralta (DDG 115) enforces the U.S. blockade of Iranian ports against M/T Stream after it attempted to sail to an Iranian port, April 26. (CENTCOM X) CANBERRA: President Donald Trump’s Project Freedom lasted just two days. The United States mission to guide ships through the Strait of Hormuz supported only two vessels exiting the Gulf before it was suspended on Tuesday (May 5). Iran had disrupted the critical waterway – through which roughly 20 per cent of global oil supply passes – to gain leverage in the war. Given the impact on the global economy, one question might seem obvious: Why has the US Navy, the world’s most powerful navy, not simply restored safe passage through the strait? The answer is more complicated than either side’s rhetoric suggests. In the opening weeks of the conflict, Mr Trump indicated he could reopen the strait with relative ease. He called on allies and partners, including Japan and Australia, to help provide naval escorts. They declined. The assumption underpinning this was straightforward: Overwhelming naval power should be able to keep the narrow waterway open. Confidence in the Strait of Hormuz Despite political declarations and media headlines, the strait is neither fully open nor fully closed. Commercial shipping has been deterred because shipowners, insurers and crews do not believe it is safe. More than 40 merchant vessels have reportedly been attacked or harassed by Iran in the Strait of Hormuz, the Persian Gulf and the Gulf of Oman since the conflict began. Adding to the uncertainty are Iranian claims that sea mines have been laid in the normal transit route through the strait. The Pentagon told US lawmakers mine clearance could take up to six months. Iran has also directed ships to pay a toll to move through Iranian territorial waters, with reports this week that Tehran has unilaterally created the “Persian Gulf Strait Authority” to enforce its new transit rules. The cumulative effect has been to sharply reduce maritime traffic through one of the world’s busiest international waterways. Geography Favours Iran The problem is that forcing open the Strait of Hormuz would be an asset-intensive and operationally demanding mission. The challenge of operating in this chokepoint is geography. Iran’s position along the northern edge of the Persian Gulf, Strait of Hormuz and Gulf of Oman allows it to use relatively cheap cruise missiles, uncrewed aerial vehicles and small boats to threaten shipping with very limited warning time. US warships supported by airpower can defend themselves and limited groups of escorted vessels against these attacks. But doing so over prolonged periods is demanding on crews and rapidly consumes missiles that cannot be replenished at sea. While there is no fixed ratio, it is unlikely a single US destroyer could effectively protect more than two or three merchant ships transiting the Strait at one time, particularly given that the merchant vessels themselves have no ability to defend against these threats. Any sustained escort operation would also require extensive intelligence, surveillance and reconnaissance support across the Persian Gulf, Strait of Hormuz and Gulf of Oman, as well as coverage of Iran’s coastal areas to provide early warning of attacks. Combat air patrols would need to remain overhead, supported by helicopters ready to respond to drone or small boat attacks on shipping. Maintaining this effort over time would likely also require limited marine corps raids against Iranian Revolutionary Guard launch sites along the coast or on Iranian-held islands. High Risk, Limited Reward Even if a large-scale escort effort were feasible, it would only be capable of moving a fraction of the usual transit volume safely through the waterway. Around 130 vessels normally pass through the Strait of Hormuz each day. Project Freedom managed two ships in two days, underscoring the reality that even a substantial military effort – involving warships, aircraft and surveillance assets – would not come close to sustaining normal shipping flows. These realities help explain why Washington initially avoided large-scale escort operations, before announcing Project Freedom. The mission was intended to guide limited numbers of ships through the strait using destroyers, more than 100 aircraft and 15,000 military personnel – not to restore normal commercial traffic. Even that limited ambition proved challenging. Regional partners appeared unconvinced that the mission could remain limited. Project Freedom was reportedly suspended in part after Saudi Arabia refused US access to its airspace and bases. This likely reflected concerns that the military operation could quickly escalate into direct confrontation. Iran had repeatedly warned that foreign warships escorting commercial traffic through the strait would be treated as hostile actors. The Limits of Naval Power in the Gulf Lost amid the geopolitical signalling is the plight of merchant mariners themselves, with more than 20,000 seafarers thought to be stranded in the Gulf. A limited, but protected corridor, would have enabled more vessels and stranded seafarers to leave the Gulf safely. But that option has receded for now. And so, they remain trapped, unable to transit through the Strait of Hormuz due to fears of Iranian attacks, with no clear timeline for a return to normal shipping operations and no immediate plans for the US or a multinational coalition to come to their rescue. The abrupt pause of Project Freedom has added further uncertainty and likely undermined confidence in the US. Even overwhelming naval power has its limits. The events playing out in the Strait of Hormuz are demonstrating this in real time. Warships can reduce risk and provide reassurance, but they cannot easily restore commercial confidence in a contested maritime chokepoint.

22 April 2026 | Jennifer Parker *Originally published in Lowy's The Interpreter on 22 April 2026 Image: HMAS Canberra and HMAS Warramunga while on deployment on the East Coast of Australia (Defence images) In 2023, the Australian government adopted a “strategy of denial” to guide defence planning, defined as an “defensive approach designed to stop an adversary from succeeding in its goal to coerce states through force, or the threatened use of force, to achieve dominance.” The 2026 National Defence Strategy and its associated Integrated Investment Program, released last week, offer the next steps in achieving this plan, with maritime capabilities a crucial component. But gaps remain. The 2026 Strategy is careful to distinguish a strategy of denial from a strategy of sea denial. Sea denial, as seen in the Black Sea or the Strait of Hormuz, can restrict an adversary’s freedom of manoeuvre, but it does not guarantee our own. Securing freedom of manoeuvre across the maritime domain through sea control is essential to protecting long sea lines of communication and enabling maritime power projection. The 2026 Strategy recognises this, committing to work with allies and partners to protect Australia’s critical sea lines of communication, reinforced by ADF tasks focused on defending economic connections and strengthening maritime domain awareness. It also broadens the concept of maritime strategy, with a stronger focus on defence industry policy and supply chain resilience. Reducing the volume of critical goods that must move by sea is an important part of any effective approach. This reflects an attempt to take a more national view, but sits awkwardly in what is still a military strategy and would be better developed in a whole of government maritime strategy. Sea denial can restrict an adversary’s freedom of manoeuvre, but it does not guarantee Australia’s own. The 2026 Strategy sets out 11 priorities for the integrated force, many with a clear maritime focus. It includes undersea warfare to project force, hold an adversary at risk and maintain situational awareness. It extends to maritime capabilities for sea denial and localised sea control to deny access and enable ADF freedom of action, and amphibious capability. These themes were evident in the 2024 edition of the strategy but are now more clearly expressed. Even so, the 2026 Strategy is still not clear on how Australia would protect its sea lines of communication. It would have been stronger if this had been set out as a layered, whole of government approach, rather than left to be inferred. The Integrated Investment Program released alongside the 2026 Strategy outlines the prioritised capability investments to implement the longer-term vision. The maritime elements of the capability investment program remain largely the same as in 2024. Of the 11 capability priorities outlined in the investment program, several are maritime, including undersea operations, sea denial and localised sea control, and amphibious army capability supported by investment in targeting and missile. Maritime capability still makes up a large share of the investment program, at around 41%. In line with Defence announcements over the past year, the Integrated Investment Program reinforces the central role of nuclear-powered submarines under the AUKUS arrangement. It also places growing emphasis on extra-large and large uncrewed underwater vehicles such as Ghost Shark and Speartooth. While their full capabilities are not public, their likely intelligence, surveillance, reconnaissance and strike roles should help bridge the gap between the ageing Collins-class and the future Virginia-class submarines. These uncrewed underwater vehicles are also likely to play an important role in seabed warfare, an area of increasing focus. Whether this will be sufficient remains uncertain. A positive shift in the Integrated Investment Program is the broader view of maritime capability, with renewed attention to areas such as hydrography and mine warfare that were largely overlooked in the 2024 version. But the added detail is not matched by a clear plan or funding to close the capability gaps in the earlier version. The Integrated Investment Program includes references to autonomy and uncrewed systems helping to address these shortfalls, but it remains unclear how, likely reflecting budget constraints. As it stands, the approach leans heavily on the promise of autonomy without explaining how it will deliver. On localised sea control – where the distinction with a strategy of pure sea denial becomes important – this task rests with the surface combatant fleet of frigates and destroyers, consistent with the selection of the upgraded Mogami general purpose frigate in August 2025. While the expanded capability will be considerable, these ships will not arrive until the 2030s and 2040s. In the meantime, the present fleet of ten surface combatants – including seven ageing Anzac-class ships – will fall to nine in 2026 and not grow again until the first Mogami enters service around 2030. There is no ambition to accelerate the Hunter class frigates, not expected until 2034. The Large Optionally Crewed Surface Vessel announced in 2024 curiously remains, despite indications the US will move away from this – leaving Australia’s ambition feeling rather aspirational. Replenishment is a more immediate gap. The ability to keep ships at sea through replenishment is scarcely addressed in the Integrated Investment Program. After cancelling the future multi role vessels in 2024, the investment program maintains that two replenishment ships are enough. They are not. This does not support continuous operations and provides no real resilience. It remains a clear capability shortfall. The 2026 Strategy describes a more dangerous and unpredictable era, with higher levels of state conflict than at any time since 1946, and acknowledges Australia’s core maritime vulnerability of sea lines of communication, yet the 2026 Integrated Investment Program still does not provide the ability to protect it over the next five years – a risk that is compounding.

20 April 2026 | Jennifer Parker *Originally published in the Australian Financial Review on 16 April 2026 Does Australia have the capability to defend itself and protect its maritime lifelines? Under the current funding profile, the answer is no, we would be relying on the United States to do it for us. The second iteration of the National Defence Strategy arrives against the backdrop of conflict in the Middle East already affecting Australia’s fuel, fertiliser, plastics supply and more. The petrol pump is a visible reminder that, as an island nation with the world’s third largest exclusive economic zone, our critical vulnerability lies in our dependence on secure maritime supply chains to sustain the economy and our capacity to fight. The strategy recognises this reality and reflects a more dangerous strategic environment. But despite the rhetoric and announced increases in defence spending , it is likely to remain a well-written document that is not properly resourced, cannot be delivered, and leaves Australia no safer. Defence spending quickly becomes emotive. Some call for 5 per cent of GDP with little explanation of what capability that would buy. Others argue any increase comes at an unnecessary impact on health, education and housing. Neither view is serious. At its core, defence spending is about risk. It is about whether Australia has the capability to defend itself and protect the flows of fuel, food, fertiliser and goods that keep the country functioning. As we are learning in the current fuel supply crunch, the flow of these critical supplies are the foundations of economic stability and national power. Defence capability is, in effect, an insurance policy against conflict and coercion. Put plainly, wars are becoming more frequent, and the chances of Australia being drawn into one are increasing. And the risk is rising. In recent years there has been more state-on-state conflict than at any time since the Second World War. The strategy itself notes that “international norms against the use of force and coercion are weakening, with more states already engaged in conflict at the start of 2024 than at any point since 1946”. Put plainly, wars are becoming more frequent, and the chances of Australia being drawn into one are increasing. The problem is not the strategy. It is the funding. As Defence Minister Richard Marles said in 2023, “strategy without money is just hot air”. He was right. Yet, that is where we find ourselves in 2026. The government has committed an additional $14 billion over the next four years and $53 billion over the decade. That sounds substantial. It is not. The claim that defence spending will reach 3 per cent of GDP by 2033 relies on a revised measure that includes items such as veterans’ pensions, which do not generate capability. Under traditional measures, spending sits closer to 2.3 to 2.5 per cent of GDP. This is the first government in a decade to lift defence spending, which deserves acknowledgment. But the increase is marginal when measured against the capability required and the risks Australia now faces. As a share of the economy, spending remains below Cold War levels, despite a far more complex and contested strategic environment. The government has been keen to highlight its record compared with previous governments, which is a clear increase and improvement. But the strategy itself makes clear that the risk of conflict is significantly higher than it was even two years ago. Spending has increased. The risk has increased faster. The test is simple: does Australia have the capability to defend itself and protect its maritime lifelines? Under the current funding profile and Integrated Investment Program, the answer is no, we would be relying on the US to do it for us. A central theme of the strategy is greater self-reliance within the alliance. Yet, Australia’s Defence Force today has less capacity overall to operate independently and execute key missions than it did during the Cold War. Despite the focus on the maritime domain, Australia still has just 10 surface combatants, about 70 per cent of which are ageing and of limited utility in modern naval warfare. Sustainment is constrained, with only two replenishment ships to keep the fleet at sea. Reforms welcome Protecting maritime trade is not simply a numbers game, but even on that measure the gaps are obvious. While Thursday’s announcements will improve mine warfare and seabed capabilities, on the face of things they do not appear to close the broader gap. Much has been achieved over the past two years. There have been reforms to procurement, progress in domestic missile production and acquisition, and long-term plans to expand the navy through new surface combatants and nuclear submarines. But as risk has increased, decisions should have been taken to accelerate the Hunter-class frigates, consider additional or upgraded Mogami-class vessels, expand replenishment capacity, and rapidly address mine warfare shortfalls. Those decisions have not been made, most likely due to resourcing constraints. The strategy is sound, but it is not matched by the resources required to deliver it. The fiscal outlook is constrained, with inflationary pressures and even the International Monetary Fund calling for governments to rein in spending. That does not make this an easy ask, but it does not make it any less necessary. However defence spending is measured, the question is capability. Do we have what is required to defend Australia in a more dangerous world? We do not. The plans announced on Thursday do not change that. Until they do, the strategy will remain constrained by funding, and Australia will remain exposed.

15 April 2026 | Jennifer Parker *Originally published in the Sydney Morning Herald Image: Australian Army officer Colonel Susan Coyle, CSC, Commander Task Group Afghanistan, at the graduation ceremony for 3rd Kandak. With wars in Europe and the Middle East, and Chinese naval task groups operating closer to Australia, the familiar line that this is our most challenging strategic environment since World War II is starting to feel dated. We are certainly in a more dangerous period. That is the backdrop to today’s leadership announcements: Vice Admiral Mark Hammond as the next Chief of the Defence Force, Rear Admiral Matt Buckley as Chief of Navy, and Lieutenant General Susan Coyle as Chief of Army will lead the ADF through this. Coyle’s appointment stands out. Not just because she is the first woman to lead a service, but because she is the first Chief of Joint Capabilities to step into the role, bringing experience in cyber , space and the enabling elements of how the ADF fights. I first met Lieutenant General Coyle in the Middle East at Al Minhad in January 2020. The United States was pursuing “maximum pressure” on Iran over their nuclear program, a context that feels familiar again today. At the time, she was commanding Australia’s Middle East headquarters. Just days earlier, General Qasem Soleimani had been killed by the United States in Iraq. I had deployed to lead planning within the International Maritime Security Construct , established to protect shipping through the Strait of Hormuz after Iranian attacks on commercial vessels. As I walked out of the mess, then Major General Coyle called out and introduced herself. Hundreds of Australians pass through that base, but she knew who I was and wanted to talk about the maritime reassurance mission I was there to support. She was already deeply experienced in the Middle East, including as deputy commander joint task force 636 in Afghanistan, where she was awarded a distinguished service medal. What stood out was her mission focus but also the time she took to get to know her people. When COVID hit and rotations were extended, that did not change. Despite running operations across a tense region where war remained on the cards she made time to stay connected. She even dialled into the Zoom trivia nights I ran for my team to keep morale up during a difficult period, the only person who managed to get my random trivia questions about my home town of Broken Hill correct. That balance between mission focus and genuine care for her people was clear then, and it is why her appointment matters. Coyle’s appointment is not about gender. But it is significant that she is the first woman to lead one of Australia’s armed services. It reflects not only her leadership, but the contribution of those who came before her. It traces back to the women of the Australian Women’s Army Service, and the other service equivalents who answered the call in wartime, only to be discharged when it ended. It includes the women of the Women’s Royal Australian Army Corps and their navy and air force equivalents who, after the re-establishment of women’s services in the early 1950s, were required to leave upon marriage, and later on becoming pregnant. It includes those who pushed to be deployed and argued for access to operational roles, expanding what was possible until all roles in the ADF were opened to women in 2013. All of that effort, often unrecognised at the time, has contributed to this moment. The appointment of Australia’s first female service chief is not just about one individual, but the cumulative effect of those who were constrained by policy, limited by expectation or passed over despite their capability. It is, in many respects, overdue. The navy was the first to deploy women to sea in operational roles in the early 1990s. Yet it has still not appointed a female warfare officer to two-star rank, let alone three-star or chief of service. By contrast, the army has produced a number of female three-star officers. Lieutenant General Coyle’s experience as commander of information warfare and chief of joint capabilities also points to where the army is heading. As the first service chief to come from joint capabilities command, she brings a clear focus on integration, not just across the joint force, but with emerging technologies, particularly space and cyber . This is probably a deliberate choice, reinforcing and accelerating the transformation already under way under Lieutenant General Simon Stuart. Today is a significant moment. Three officers have been appointed at a time when the world is becoming more dangerous, to lead the ADF and prepare Australia for what lies ahead. That task will not be easy, and they deserve our support.

10 April 2026 | Jennifer Parker *Originally published in The Conversation on 10 April 2026 Image: A photo released by the Royal Thai Navy showing the Thai-flagged bulk carrier Mayuree Naree shortly after it was hit by Iranian projectiles 11 nautical miles off the coast of Oman in the Strait of Hormuz, Mar. 11, 2026. Royal Thai Navy Share article Print article Wednesday’s ceasefire announcement by President Donald Trump, linked to Iran reopening the Strait of Hormuz, prompted immediate optimism shipping would quickly resume. It didn’t. The following morning, traffic remained minimal . A handful of vessels, largely linked to Iran, made the transit. But most of the ships waiting in the Gulf stayed put. Iran announced shortly afterwards that it would effectively close the strait because of Israel’s attacks on Lebanon. The reality is the strait was never closed . Framing the issue as “open” or “closed” misses the point. Ships are not being physically blocked. They are being deterred . Over recent weeks, Iran has demonstrated both the capability and intent to target commercial shipping. Attacks and credible threats against vessels have driven daily transits down from around 130 to just a handful. Until that risk changes, ships will not return in meaningful numbers. So what can be done to turn this around? Both walking and talking The ceasefire declarations have added to the uncertainty rather than resolved it. Washington has asserted that the strait is open . Tehran’s messaging has been more ambiguous, including references to requiring vessels to inform Iranian authorities before transiting. Some interpret this as a precursor to attempts to exert control over the waterway through a toll . This ambiguity matters. Shipping is a commercial activity driven by risk calculations. Operators and crews will not move on the basis of political statements, particularly when recent experience suggests those statements may not hold. The importance of reassurance In practice, restoring traffic through the strait will likely occur in two phases. The first is reducing the threat. That can occur through military means, diplomacy, or a combination of both, but it must materially degrade Iran’s ability and willingness to target shipping. The second is reassurance. Even if Iran’s attacks on civilian shipping stop as a result of the ceasefire, shipping will not immediately return. Confidence has been shaken and will take time to rebuild. A credible reassurance effort would include limited naval escorts, at least initially. It’s notable the US did not move immediately to demonstrate confidence in the ceasefire by escorting US flagged and crewed commercial vessels out of the Gulf. That would have sent a clear signal to industry, helped restore confidence in transits and undercut subsequent Iranian claims that ships require approval from its armed forces. Given Iran’s interest in maintaining the ceasefire, it would have been unlikely to challenge ships under US naval protection. The US hesitation has instead created space for Iran to entrench its position, pushing vessels closer to its coastline and reinforcing its ability to shape how the strait is used. An effective reassurance campaign would also involve a broader international presence to provide surveillance, information-sharing and rapid response capability. The international community should move quickly to establish this. Its very establishment would help restore confidence in transits. We have seen this model before. The International Maritime Security Construct , established in 2019 following Iranian attacks in the Gulf of Oman, focused on transparency, coordination and reassurance rather than large-scale convoy operations. I served as the construct’s Director of Plans in 2020. A similar, but more effective, approach is likely to be required again. It is not a silver bullet, but reassurance is layered, and this would at least provide the clarity and communication shippers need. Diplomacy will also matter. Clear, coordinated messaging from the international community, backed by explicit economic consequences for any renewed attacks on merchant shipping, will be essential to rebuilding confidence. The question of tolls There has also been speculation about whether Iran might seek to impose a toll on vessels transiting the strait. The legal position here is clear. The Strait of Hormuz is an international strait under the United Nations Convention on the Law of the Sea. Ships enjoy the right of transit passage through the strait. Charging vessels for passage would cut directly against that principle and set a dangerous precedent for other strategic waterways. There are early signs Iran is testing the boundaries. Reports of radio calls warning vessels they require approval to transit, and suggestions that ships should notify Iranian authorities before transiting, point to an attempt to exert greater control over the strait. That should be resisted. Allowing a toll, or even limited restrictions, to take hold in the Strait of Hormuz would have far-reaching consequences, undermining the central principle of maritime trade: freedom of navigation. Regardless of Donald Trump’s flippant comments , the international community is unlikely to accept any enduring Iranian toll system. If Iran attempts to pursue one, it should face clear economic consequences, including sanctions. Questions remain about whether mines have been laid in or near the strait. Even the suggestion adds to uncertainty and reinforces the need for a coordinated international response, including transparent assessments of the threat environment. A clear, public assessment from the international community on whether the strait has in fact been mined would go a long way. It should be an early priority for any coalition effort. The bottom line Ultimately, shipping will return to the Strait of Hormuz not when it is declared open, but when it is assessed to be safe enough. That will require a sustained period without attacks, a visible international effort to secure the waterway, and clear signalling that the rules governing international straits will be upheld. Until then, the ships will wait.

Jennifer Parker | 1 April 2026 *Originally published in the Sydney Morning Herald 31 March 2026 Image: The Astute-class submarine HMS Anson arrives at HMAS Stirling in Western Australia for a scheduled Submarine Maintenance Period (SMP). Australians feeling the sting of high fuel prices at the bowser, or seeing supplies struggle to reach regional communities, are being reminded just how dependent Australia is on the arrival of supplies by sea. That dependence sits at the centre of our economic prosperity and our security. It is why AUKUS, and the move to nuclear-powered submarines, matters. Most Australians would know by now that concerns about global oil supply are, at their core, a maritime problem. The Strait of Hormuz, a narrow body of water between Iran and Oman, carries about 20 per cent of the world’s oil. Despite some reporting, the strait is not closed. But Iran has effectively deterred much of the traffic that would normally pass through it, including about 30 oil tankers and more than 100 other vessels each day. This disruption has not required large-scale attacks. Iran has struck about 21 ships, but it has been enough to unsettle shipping and drive up risk. It has done this despite the presence of the United States military, because geography is on its side. Iran’s coastline runs along the northern edge of the Arabian Gulf, the Strait of Hormuz and into the Gulf of Oman, giving it a natural advantage. In maritime security, geography matters. For Australia, as an island nation spanning three oceans, it defines our exposure. Our critical supplies, fuel, fertiliser, pharmaceuticals, plastics and more, all arrive by sea. In a conflict involving Australia, the challenge is not just a single chokepoint, although some would matter. It is the scale of the maritime domain around us, the distances involved, and the difficulty of protecting trade against capable naval forces. If that were to occur, the impact would go well beyond higher fuel prices. It would mean disruptions to the flow of critical supplies across the economy, with real consequences for how Australians live. Australia’s ability to protect these seaborne supplies will be critical in any crisis or conflict. That is a demanding task given the scale of our maritime domain and the length of our trade routes. To operate across those distances, Australia needs the right capability. That is why Australia is acquiring nuclear-powered submarines. There are many advantages to nuclear submarines, but two matter most for Australia. The first is speed. Distance is our defining challenge. A Collins-class submarine takes around eight to 12 days to transit from Perth to Sydney, or to the Sunda Strait, a key route for Australia’s trade through the Indonesian archipelago. A nuclear-powered submarine can do the same in around four to five days. A conventional submarine would also need to raise a snorkel mast multiple times during that transit, increasing the risk of detection. A nuclear-powered submarine does not. Nuclear-powered submarines are not the only capability required, but they are central to operating across the distances that define Australia’s maritime domain. Australia’s debate on AUKUS is increasingly filled with claims that the program is failing or “headed for a train smash”, as a former submarine commander warned. The three-phase pathway does carry risk, and no one has suggested it will be easy. But much of this criticism is long on assertion and short on analysis or credible alternatives. The challenges facing AUKUS are real, but are not unique. The US and UK are working through constrained industrial bases, and those same pressures exist across every submarine-producing nation. Walking away would not remove these constraints, it would simply delay capability and deepen the very gap critics warn about. The risk is real. But in complex defence capability, risk is managed, not avoided. Abandoning it because it is difficult is not a serious option, particularly as, despite alarmist rhetoric, the program remains on track. For Australia, the question is not whether AUKUS is difficult. It is whether there is a more credible way to deliver the reach, endurance and persistence needed to operate across our maritime domain. To date, no alternative has answered that. Calls to cancel AUKUS avoid the harder question of what comes next. They do not solve the problem, they risk leaving Australia without a credible submarine capability for a period of time. As the war with Iran has shown, it does not take much to disrupt a key maritime corridor. Australia faces a different geography, but the same logic applies. Our vulnerability is defined by our reliance on seaborne supply, and the distances involved in protecting it. The answer, therefore, is also maritime. It requires the ability to project power across our approaches and protect the flows our economy depends on. As Australians are seeing, even a limited disruption at sea has immediate consequences at home. As our strategic environment deteriorates, this fuel shock will look minor compared to the economic and security impact of disrupted maritime trade. That is the risk Australia faces. A stronger focus on maritime power, including nuclear-powered submarines, is about ensuring we can protect it. It is also a question of confidence. Australia has built and sustained complex defence capabilities before. There is no reason to assume this one is beyond us.

Jennifer Parker | 26 March 2026 *Originally published in War on the Rocks on 26 March 2026 Image: US DOD. Sinking of IRIS Dena A U.S. submarine recently sank an Iranian warship in one of the world’s busiest maritime corridors. Many overlooked the incident’s significance. Others misunderstood what had occurred. The sinking of the IRIS Dena in the Indian Ocean, roughly 40 nautical miles off Sri Lanka’s southern coast, was a graphic reminder of the brutality of war on the high seas. Footage of the ship’s stern exploding and images of Sri Lankan Navy personnel rescuing survivors quickly circulated online, prompting fierce debate about the legality of the strike and the nature of combat at sea. It also exposed a broader problem. Naval warfare remains poorly understood outside naval circles. The IRIS Dena was a lawful target under the law of naval warfare. It is also long recognized in international law scholarship that modern submarines cannot safely surface to rescue survivors. Their obligation is instead to notify appropriate vessels or authorities so that rescue can be undertaken as soon as practicable. Yet, misunderstandings of these aspects dominated early reporting. The wider conflict between the United States, Israel, and Iran had begun on Feb. 28, only days before the IRIS Dena was sunk. Within days, degrading Iranian naval capability had emerged as a key operational objective. The sinking of the IRIS Dena did not occur just anywhere. It took place along one of the world’s most consequential trade routes in the Indian Ocean, a corridor critical to global energy flows and to China’s economic security. The engagement was not only a tactical success but also a broader strategic signal. In the immediate online reaction to the sinking, narrative often overtook fact. So, what happened in the Indian Ocean, and why was it lawful? Iran’s Naval Presence Beyond the Gulf Just after 5 a.m. on March 4, approximately 40 nautical miles south of Galle, the IRIS Dena was sunk by a Mark 48 heavyweight torpedo fired from the USS Charlotte . The ship was a relatively new multi-role frigate, launched in Iran in 2015 and commissioned into service in 2021. One of seven Moudge-class frigates operated by the Iranian Navy , the vessel displaced roughly 1,500 tons, placing it closer in size to a corvette or offshore patrol vessel than a traditional frigate. Despite its modest dimensions, it carried a crew comparable to many larger surface combatants, with a normal complement of around 140 personnel. Reports suggest between 130 and 180 personnel were onboard when the ship was sunk. Despite claims that the vessel was unarmed , the IRIS Dena was reasonably capable for its size, though no realistic match for a nuclear-powered attack submarine. Open source assessments indicate the ship carried a 76 mm naval gun, surface-to-air missiles, anti-ship missiles, triple 324 mm torpedo launchers, and a hull-mounted sonar . Warships rarely transmit on hull sonar while transiting unless a submarine threat is suspected. In practice, this distinction is unlikely to have mattered. The attacking submarine likely fired from well beyond detection range. The IRIS Dena would therefore have had little warning of the strike, and even if contact had been gained, its lightweight torpedoes would have offered only limited defensive options. Since commissioning, the IRIS Dena had become a visible instrument of Iranian naval diplomacy. A 2023 deployment with the converted tanker IRIS Makran was designed to signal Iran’s intent to operate well beyond the Persian Gulf and build a more credible blue water naval capability. In February 2026, the frigate was operating in the Indian Ocean after participating in India’s International Fleet Review in Visakhapatnam and the multilateral Exercise MILAN alongside the Iranian landing ship IRIS Lavan . It was reportedly transiting back toward Iran when attacked. Another Iranian tanker, the IRIS Bushehr , was also operating in the region in support of the task group. Misinformation in the Maritime Domain Shortly after the sinking, inaccurate reports circulated claiming that the IRIS Dena had been unarmed , with some suggesting that participation in India’s International Fleet Review required vessels to sail without weapons. The fleet review and Exercise MILAN brought together more than 60 ships and aircraft from around 70 countries. While there would have been guidelines governing conduct during the events, there was no requirement for participating warships to be unarmed or to sail without ammunition. In years of planning and participating in multinational naval exercises across the Indo-Pacific, such a requirement is not one I have encountered. The sea phase of Exercise MILAN also appears to have included live-fire activities, further undermining claims that participating vessels were required to be unarmed. Although the precise loadout of the IRIS Dena cannot be confirmed from open sources, it would be highly unusual for a warship to transit the Indian Ocean to a multinational exercise without its normal weapons and ammunition, particularly at a time of heightened tensions between Iran and the United States. For a commanding officer to deploy and remain at sea in such circumstances without an appropriate combat load would raise serious professional questions. More broadly, the episode illustrates how quickly misinformation can take hold in the modern information environment, especially when naval operations occur far from public view and public understanding of maritime warfare remains limited. A Submarine Engagement at Range The IRIS Dena was reportedly seeking permission to enter Sri Lankan waters when it was engaged by the USS Charlotte. Washington has not publicly outlined the sequence of the engagement. Media outlet Iran International claimed that one sailor who died in the sinking contacted his parents to say the vessel had been warned by American forces to abandon ship. This account has not been verified and would be unusual in the context of a submarine engagement. The attacking submarine is understood to have fired a Mark 48 torpedo, detonating beneath the stern of the IRIS Dena. Following the sinking, the Sri Lankan Navy conducted rescue operations with initial reports indicating the recovery of 32 survivors and 87 bodies, with a further 61 crew members still missing. The speed of the response suggests local authorities may have been alerted before the vessel sank. Some reports indicate the ship transmitted a distress call shortly after 5 a.m., while the U.S. Navy has confirmed that it notified Sri Lankan authorities of the incident. The engagement also attracted attention in Australia after the prime minister confirmed that three Australian sailors were embarked on the U.S. submarine at the time, though they were not involved in the strike. What the Law of Naval Warfare Permits The sinking also prompted debate about neutrality and the legal implications of Australian sailors embarked on the attacking submarine. These issues warrant separate consideration but do not alter the lawfulness of the strike. The more immediate questions are straightforward: Was the Iranian warship a lawful military target, and was there an obligation to rescue survivors? Established principles of the law of naval warfare provide clear answers. The law of naval warfare forms part of the broader law of armed conflict and applies specifically to the conduct of hostilities at sea. Under this framework, warships of a belligerent state are lawful military objectives by virtue of their status. Once an international armed conflict exists between states, their military vessels may be attacked wherever they are encountered on the high seas or in belligerent waters, subject to the rules governing the conduct of hostilities. In practical terms, this means that a vessel such as the IRIS Dena could be lawfully targeted because it formed part of the armed forces of a belligerent state and contributed to its military capability. The fact that the ship was operating in the Indian Ocean rather than close to Iranian waters does not alter this legal assessment. Naval warfare has long been conducted across vast maritime spaces, and belligerent warships have historically been engaged wherever they are found on the high seas. A second issue concerns the obligation to rescue survivors. The law of armed conflict at sea recognizes a duty to assist those who are shipwrecked, wounded, or otherwise no longer able to take part in the fighting. This obligation, however, is not absolute. Commanders are not required to undertake rescue operations where doing so would place their own vessel or mission at serious risk. This qualification is particularly relevant in submarine warfare. Unlike surface combatants, submarines rely on stealth for survivability. Surfacing to conduct rescue operations may expose them to detection and attack. In such circumstances, humanitarian obligations may instead be met by alerting nearby authorities or other vessels capable of conducting rescue operations. Reports that the United States notified Sri Lankan authorities of the sinking of the IRIS Dena would be consistent with this obligation. In naval warfare, the duty to assist survivors must ultimately be balanced against the operational realities of fighting at sea, a limitation generally recognized in international law. Conflict Along Critical Sea Lines of Communication The sinking of the IRIS Dena was more than a tactical success in the war between the United States, Israel, and Iran. Conducted along one of the world’s most important maritime trade corridors, the engagement carries strategic implications that extend well beyond the immediate belligerents. The incident occurred along a particularly consequential stretch of the Indian Ocean. Trade routes south of Sri Lanka carry significant volumes of global energy and container traffic linking the Middle East, Europe, and Asia. For China in particular, these sea lines of communication are central to sustaining economic growth and long-term energy security . The willingness and demonstrated effectiveness of the United States in employing force in this space will not have gone unnoticed. The engagement also served as a practical reminder of the continued effectiveness of U.S. submarine capability. While few observers doubt the lethality or reach of American undersea forces, the sinking demonstrated in operational terms the difficulty surface vessels face in detecting and countering modern submarines. In this sense, the incident was not only about Iran. It also sent a broader signal about the willingness and ability of the United States to employ military force at range in defense of its interests. For some audiences this reinforces deterrence — for others it heightens concern about escalation along critical maritime trade routes. Naval Warfare’s Enduring Logic The sinking of the IRIS Dena was a stark reminder that naval warfare follows its own logic. Engagements can occur far from home waters, unfold with little warning, and carry consequences well beyond the immediate tactical exchange. In this case, a single submarine strike intersected with global trade flows, alliance dynamics, contested information environments, and the legal realities of conflict at sea. For policymakers, the episode underscores the need to understand maritime warfare not as a peripheral concern but as a central feature of contemporary strategic competition. For naval commanders, it reinforces enduring truths about stealth, reach, and the unforgiving nature of combat at sea. More broadly, the incident signals that the United States remains willing to employ force along critical sea lines of communication when it judges such action lawful and strategically necessary. Maritime power is again shaping strategic outcomes in the Indo-Pacific.