The Indo-Pacific is rapidly emerging as the central theatre of global strategic competition. Unlike the Cold War in Europe, where nuclear deterrence involved two superpowers across relatively defined front lines, the Indo-Pacific presents a far more complex landscape. The region spans vast maritime distances, multiple potential flashpoints, and several nuclear-armed adversaries. North Korea continues to expand its nuclear and missile programs, China is rapidly increasing both the size and sophistication of its arsenal, and Russia maintains nuclear capabilities alongside a growing strategic presence in the Pacific.

In such an environment, the traditional model of extended deterrence, where the United States alone provides nuclear protection to its allies, may not be sufficient to address the scale and diversity of contingencies across the region. A new framework may be required, an Indo-Pacific nuclear alliance built on shared responsibility, distributed deterrence, and sovereign nuclear capabilities among key allies.

Complicating the adversary: The logic of distributed deterrence

At the core of such an alliance would ideally be sovereign nuclear deterrents for Australia, Japan, and South Korea. This model would resemble the role of the United Kingdom and France within NATO. Both maintain independent nuclear forces and sovereign decision-making, while contributing to the alliance’s broader deterrence posture.

Applying this model to the Indo-Pacific would significantly strengthen deterrence. If Australia, Japan, and South Korea each possessed sovereign nuclear capabilities, adversaries would face a far more complex strategic calculus. Rather than confronting a single decision-maker in Washington, they would need to account for multiple independent governments capable of responding to aggression.

This distributed architecture would complicate adversary planning and raise escalation risks. Any state considering coercion or military action against an Indo-Pacific democracy would have to account not only for the United States, but for several nuclear-capable regional powers with distinct strategic interests and decision-making processes.

Geography reinforces this logic. The Indo-Pacific spans an immense area, from the Korean Peninsula and Taiwan Strait to the South China Sea and the Indian Ocean approaches to Australia. The sheer distance between these theatres makes a purely centralized deterrence model increasingly difficult to sustain.

Flexible Deterrence through forward deployment and hosting

An Indo-Pacific nuclear alliance would therefore require forward deployment and hosting arrangements across the region. Australia, Japan, and South Korea could host a range of nuclear capabilities designed to provide flexible deterrent options across multiple contingencies.

These could include submarine-launched ballistic missiles (SLBM-N) on Ohio- and Columbia-class submarines; nuclear sea-launched cruise missiles (SLCM-N) on Virginia- and AUKUS-class submarines; B83 gravity bombs for platforms such as the B-2 Spirit and B-21 Raider, alongside the rearming of the B-52 Stratofortress and B-1B Lancer; B61 nuclear bombs for the B61 nuclear bombs for aircraft including the B-2, B-21, B-52, and F-35A Lightning II; and Long-Range Stand-Off (LRSO-N) nuclear cruise missiles for the B-21 and B-52. In addition, nuclear warheads could be assigned to land-based, mobile intercontinental ballistic missile (ICBM) launchers.

By dispersing these capabilities across multiple allied territories, the alliance would establish a more resilient and survivable deterrent posture. It would be far more difficult for an adversary to neutralize. Hosting arrangements would also strengthen operational integration among allied forces. As in NATO’s nuclear-sharing model, partner nations could contribute dual-capable platforms capable of delivering nuclear payloads in extreme circumstances.

Australia, Japan, and South Korea could commit to dual-capable submarine (DCS), aircraft (DCA), and land-based missile launcher (DCL) missions within the alliance structure. Dual-capable aircraft would provide visible and flexible deterrence signaling. Submarine-based systems would ensure a survivable second-strike capability across the region’s vast maritime domain. While land-based mobile missile launchers would add a credible and responsive ground-based deterrent, reinforcing the threat of rapid retaliation.

Such arrangements would distribute both responsibility and capability among Indo-Pacific allies, reducing the burden on the United States while strengthening the credibility of deterrence. It would transform the region from one dependent on a single guarantor into a networked system of mutually reinforcing nuclear deterrents.

Why the Philippines should revisit extended nuclear deterrence

An Indo-Pacific nuclear alliance would also require a reassessment of the policies of other regional partners. One notable example is the Philippines. For decades, the Philippines benefited from extended nuclear deterrence under its alliance with the United States. However, that relationship was complicated when the Philippines ratified the Treaty on the Prohibition of Nuclear Weapons (TPNW) in February 2021. By joining a treaty that prohibits the development, possession, and use—or threat of use—of nuclear weapons, the Philippines has distanced itself from reliance on the US nuclear umbrella.
This decision sits uneasily alongside the increasingly contested security environment in the South China Sea. If Manila wishes to strengthen its security relationship with the United States and regional partners, it may need to reconsider its position. Reintegrating into the framework of US extended nuclear deterrence would provide a stronger strategic backstop against coercion or aggression in its maritime domain.

Restoring strategic stability through credible, distributed deterrence architecture

Ultimately, the purpose of an Indo-Pacific nuclear alliance would not be to encourage proliferation for its own sake. Rather, it would be to restore strategic stability in a region where the balance of power is shifting rapidly.

Deterrence works best when it is credible, distributed, and resilient. In a region as vast and strategically complex as the Indo-Pacific, relying on a single nuclear guarantor may no longer provide the level of deterrence required to prevent conflict.

By adopting a model like the United Kingdom and France within NATO, where allied states maintain sovereign nuclear forces while contributing to a broader alliance deterrence posture, Australia, Japan, and South Korea could build a more stable and credible strategic architecture.

Such an arrangement would ensure that any adversary contemplating aggression in the Indo-Pacific would face not one nuclear power, but several, each capable of defending its sovereignty and contributing to the collective security of the region.

Natalie Treloar is the Australian Company Director of Alpha-India Consultancy, a Senior Fellow at the Indo-Pacific Studies Center (IPSC), a Senior Analyst at the National Institute for Deterrence Studies (NIDS), and a member of the Open Nuclear Network. Views expressed in this article are the author’s own.

Beyond a Pacific Defense Pact 4: Blueprint for an Indo-Pacific Nuclear Alliance was originally published on Global Security Review.

Russia, which fields an arsenal of at least 2,000 such nuclear weapons, began modernizing its arsenal of intra-theater nuclear weapons more than a decade ago. These weapons can rapidly strike European NATO member-states—primarily with lower yield warheads.

Russia’s “escalate to deescalate” strategy relies on the use of low-yield battlefield nuclear weapons could either be used to defeat Ukraine and force NATO capitulation in that conflict or win a possible war against a conventional NATO force advancing East. In short, Russia could seek a fait accompli using one or a small number of low-yield nuclear weapons in a limited capacity on the battlefield, for which NATO has no equal response.

What makes such an approach highly attractive to Russia is that NATO is unlikely to respond to a nuclear use in Ukraine or an attack on NATO’s eastern flank with nuclear weapons, because NATO’s dual-cable aircraft—fighter jets armed with B-61 nuclear gravity bombs—are not a combat-ready force that can effectively counter Russian nuclear use on a battlefield. Let me reiterate, Russia likely maintains 3,000–6,000 intra-theater nuclear weapons that vary from low to high yield and short to intermediate range. Low estimates suggest they have 2,000 such weapons.

A 2017 Defense Intelligence Agency report went deeper into Russia’s tactical nuclear warfare commitment revealing delivery systems that include air-to-surface missiles, short-range ballistic missiles, gravity bombs, depth charges for medium-range bombers, tactical bombers, and naval aviation, as well as anti-ship, anti-submarine, and anti-aircraft missiles and torpedoes for surface ships and submarines. While it is only speculation, it is reasonable to suggest that Russian President Vladimir Putin was building a nuclear capability for a circumstance like he finds himself in now.

As two and a half years of war in Ukraine illustrate, Russia does not maintain a conventional force sufficient to defeat an American-led NATO force. This leaves Putin more reliant on his nuclear forces.

Given Russia’s economic and strategic limitations, it should come as no surprise that Russia has pursued low-yield battlefield nuclear weapons as an asymmetric advantage against the United States. In many respects, Russia is pursuing a course of action not dissimilar from the New Look Policy of the Eisenhower administration.

For the Biden administration and, soon, either Kamala Harris or Donald Trump, the real threat of nuclear weapons use in Ukraine or against NATO cannot be ignored. Contrary to the mantra that all nuclear weapons are strategic and there is no such thing as a winnable nuclear war, the Russians and Chinese see things differently.

Low-yield battlefield nuclear weapons do not create a nuclear wasteland. In fact, an air burst at the right height of burst produces no fall-out at all—only heat, a blast wave, and prompt radiation that dissipate in hundreds or a few thousand yards.

With numerous low-yield nuclear options available to Russia, there is a very real need for the United States military to retrain for operating in a post–nuclear detonation environment. In a recent public discussion, the heads of the Central Intelligence Agency and the United Kingdom’s MI6 revealed that Putin came very close to using a nuclear weapon in Ukraine during the fall of 2022. Such a scenario can easily arise again.

American mirror imaging of Russian perspectives on nuclear use, to suggest they think like Americans and would therefore never violate the “nuclear taboo”, is a recipe for getting caught unprepared. While Russians do see nuclear weapons as different than conventional weapons, they do understand weapons effects and are not given to the hyperbole that is widespread in the United States.

The fact that American integrated deterrence was a disastrous failure in its attempt to forestall a Russian invasion of Ukraine and is failing to restore deterrence with Russia vis-à-vis Ukraine means that the Russians now understand that American sanctions and other threats are largely harmless. Since the implementation of sanctions following Russia’s invasion of Ukraine, Putin found alternative outlets for Russian exports (petroleum) and found alternate sources of imports—including military supplies.

Rather than breaking Russia, American action drove China, Iran, North Korea, and Russia together. This leaves Putin less reluctant to use nuclear weapons in Ukraine than he perhaps was before.

Of course, neither China nor Russia is seeking to start a nuclear conflict that sees the exchange of strategic nuclear weapons. That would be devastating for everyone. But the use of a small number of low-yield battlefield nuclear weapons is a different story.

Even a reluctant Biden administration, now that it is coming to an end, tossed the disarmament community’s ostrich strategy into the dustheap of history. It is now a matter of whether the United States has the will to embark on the expansive modernization effort required to fill the gap in battlefield nuclear weapons.

Adam Lowther, PhD is the Vice President for Research at the National Institute for Deterrence Studies. The views expressed are his own.

The Return of Battlefield Nuclear Weapons was originally published on Global Security Review.