The following article is part of a series of APLN analyses by experts and members assessing the implications of the Australia-UK-US (AUKUS) deal.

Australia’s decision to join with the United States and the United Kingdom to build Australian long-range nuclear-powered submarines (SSNs) has little to do with the defence of Australia. The aim is to make possible an Australian contribution to US battle plans against China which that country will view as profoundly threatening with implications also for war planning by Russia, North Korea and other nuclear-armed states.

Even leaving aside the fiscal profligacy and defence opportunity costs for Australia of the literal blank cheque issued by the Morrison government, the nuclear submarine decision takes Australia into the heart of naval warfighting in East Asia and Southeast Asia.

Further, the Australian nuclear submarine decision will have knock-on effects in Japan and the Republic of Korea, leading them not only to move their already highly capable submarine fleets to nuclear power, but also thereby heighten the likelihood they will then equip those submarines with nuclear weapons.

For several decades the US has been concerned to negate two military advances the Chinese regard as essential protection against literally existential threats. The Australian submarines will be designed primarily to contribute to negating both of those military advances.

Firstly, over the past decade China has constructed the basis for a submarine-based nuclear deterrence force that could survive the effects of an expected US attack against Chinese land-based nuclear missile sites. If Chinese nuclear missile-launching submarines can safely get out of their homeports and reach the depths of the Pacific Ocean and the South China Sea they may have a small chance of remaining undetected by highly superior US anti-submarine warfare platforms – including US and now, possible Australian hunter-killer submarines. If those Chinese SSBNs are found and destroyed, especially after US attacks on Chinese ground-launched missile silos, and US and Japanese ballistic missile defence destroying most of the missiles that are launched by China, then, in the Chinese view, China in fact has no survivable nuclear-deterrence force. Whatever the validity deterrence by a balance of vulnerability – or of terror – may have, without a survivable second strike, China has no effective nuclear deterrence against the United States.

China’s four operational nuclear missile submarines are mainly based in the north of the South China Sea on the island of Hainan. China’s militarisation of its concrete islands in the SCS is in large part motivated by a desire to provide extended defence in depth for those SSBNs.

The fundamental requirement for that capability—apart from questions of missile range, crew training and naval submarine-launched ballistic missiles (SLBM) and nuclear submarine doctrinal development—is that the submarines are able to reach the deeps of the western Pacific undetected by U.S. and Japanese anti-submarine warfare (ASW) sensor networks. Only there do they have any chance of fulfilling their intended role as a second strike nuclear deterrent force immune to U.S. attack. One key part of US ASW capabilities, in addition to the Fish Hook underwater surveillance network from Japan to the boundary of the South China Sea, are its attack submarines hunting Chinese ballistic missile submarines. Australia’s submarines could play a modest but frontline role, especially in the waters to the west of Borneo, the Philippines and Japan.

For this reason alone, China will view Australia’s decision as a wilful contribution to an existential nuclear threat to China.

The same strategic logic applies to the Russian strategic missile submarines operating from Petropavlovsk on the Kamchatka Peninsula. Russia has recently rebuilt this force with the latest Borei class submarines operating in the “strategic bastion” of the Sea of Okhotsk and beyond into the Pacific and Arctic oceans. US nuclear attack submarines track these submarines, guided by the US-Japanese-Korean network of underwater acoustic sensors and with surface and aerial anti-submarine forces.

Secondly, Australian long-range attack submarines will be deployed in Southeast and East Asian waters to protect US aircraft carrier task forces moving into position close to China for attacks on Chinese coastal facilities, as well as against Russian or North Korean land-based forces. US and coalition SSNs will hunt and try to destroy Chinese submarines lying in wait for the US carriers; or stand as one of the point guards that move in advance of US aircraft carrier battlegroups as they move around.

China has devoted a great deal of money and energy to developing the naval, air and missile capabilities to deny US carrier battle groups the access they had in the past to Chinese waters and its immediate coastal zone inside the island chain from Japan to the Philippines.

US carrier battle groups aided by Australian submarines do not in themselves constitute an existential threat to China, but they do open a vulnerability that the US would certainly not accept for itself.

Moreover, given the acknowledged risks of escalation to use of nuclear weapons in what may begin as a conventional war on the Korean peninsula, especially together with a Taiwan crisis, Australian submarines attached to US carrier battle groups may be sailing into a nuclear war.

Australian nuclear submarines may not be allocated offensive missions against Chinese, Russian or eventually, North Korean ballistic missile firing submarines. But the roles that they likely will be allocated in American naval operations in the Western Pacific, especially in aircraft battlegroups deployed against Russia, China, or North Korea, will enable US anti-submarine operations against the nuclear forces of these states.

Other lone-wolf long-distance missions for Australian nuclear submarines can be envisioned such as inserting special forces onto land, blockading straits, but none of these can justify the crushing direct cost and massive opportunity cost to the rest of Australia’s armed forces already short of essential capacity to defend Australia’s territory against actual maritime attack.

The AUKUS project for Australian nuclear submarines carries a third nuclear risk. Much has been written about the implications of damage to French amour propre, not to say export income, but the US decision to allow Australia highly preferential access to sensitive submarine technologies only allowed out of the US once before when the US gave such access to Britain in the 1950s.

For Japan and the Republic of Korea, both US allies of considerably greater military and political significance to the US than Australia, the nuclear submarine technology export to Australia will have two consequences.

Japan and South Korea both have advanced indigenously developed and constructed submarine fleets, for which they will demand equal treatment from the US, further stimulating the dynamic underwater arms race in East Asia.

But more importantly this break-out will occur at a time when powerful political elements in both countries are pressing the case for indigenous nuclear weapons. The preferred nuclear-launch platform in both countries would be from submarines.

Anxiety in both countries about China-US tensions sits alongside not-so-latent long-standing doubts about the reliability of US promises of nuclear protection. Grievances flowing from the Australian submarine deal may well feed the domestic cases for Japanese and South Korean nuclear weapons.

The timing of Mr Morrison’s announcements also merits some consideration. In our view, this project is a political stunt aimed to distract from Covid failures, please coalition constituencies, and split the Labor Party and render the Greens shrill and sidelined. In reality, it is likely that after a passage of years of staged announcements and pseudo-planning there will be little to show for it, and the enormously expensive, strategically ill-considered, and force-structure distorting project will quietly die.

But, to use Prime Minister Morrison’s phrase, “let us be clear,” in terms of Australian security, it is a gigantic nuclear election stunt that in the long run may increase the risk of nuclear war while drawing Chinese return fire on our vulnerable export sectors, including iron ore.

“To be clear” again, it is utterly mendacious of Prime Minister Scott Morrison to say that these forces have nothing to do with nuclear weapons because Australian submarines won’t be so armed, assuming it does not cross that barrier in the future if the submarines ever come to pass. As noted above, they may play a crucial role in US nuclear strike and defence operations.

This capability has everything to do with nuclear weapons and the risk of nuclear war. The net detrimental effects on strategic instability caused by supplementing US forces devoted to strategic nuclear missions in the region may be substantial, especially in the perceptions of American nuclear adversaries who may well target Australia already, and must be properly analysed and debated before any decisions are made to proceed.

About the Author

Allan Behm is Head, International and Security Affairs Program, The Australia Institute, Canberra, Australia. Allan spent 30 years in the Australian Public Service, as a member of the Australian diplomatic service, the Prime Minister’s Department, the Department of Defence and the Attorney General’s Department. He specialised in international relations, defence strategy, counter-terrorism and law enforcement policy, and more recently, climate change.

This commentary was cross-posted on the Nautilus website here.

Disclaimer: The opinions articulated above represent the views of the author(s) and do not necessarily reflect the position of the Asia Pacific Leadership Network or any of its members. The APLN’s website is a source of authoritative research and analysis and serves as a platform for debate and discussion among our senior network members, experts and practitioners, as well as the next generation of policymakers, analysts and advocates. Comments and responses can be emailed to apln@apln.network.

Image: US DOD