There is a comforting fiction at the heart of much contemporary strategic thinking: conventional military capabilities can substitute for nuclear deterrence without requiring the same political will. It is a neat idea—reassuring, technologically optimistic, and politically convenient. It is also dangerously wrong.

Deterrence does not reside in platforms, precision, or posture. It resides in belief—specifically, the adversary’s belief that you are both capable of inflicting costs and willing to do so. Strip away that second element, and deterrence collapses into theater.

This is the central problem confronting Australia and its allies as they navigate a rapidly shifting Indo-Pacific security environment. As nuclear risks grow, particularly with China’s expanding arsenal, there has been a noticeable intellectual pivot toward elevating conventional capabilities as a more “usable,” credible, and politically palatable form of deterrence. Long-range strike, autonomous systems, undersea warfare, and advanced ISR are all presented as tools that can impose meaningful costs without crossing the nuclear threshold.

However, this argument only holds if those tools are used. Too often, the debate stops at capability acquisition. Billions are spent, platforms are announced, doctrines are drafted. Yet, there is a conspicuous silence when it comes to the harder question: under what circumstances would Australia employ these capabilities in anger? What thresholds trigger their use? What risks are we prepared to accept in doing so?

Without clear answers, the signal sent to adversaries is not strength, but hesitation. Consider the logic from the perspective of a competitor. If Australia invests heavily in long-range strike but avoids articulating when it would employ it, an adversary may conclude that those capabilities are politically constrained. If grey-zone coercion, such as the deployment of sea mines, harassment of maritime assets, or interference with undersea infrastructure, does not elicit a forceful response, then the lesson learned is not deterrence, but permissiveness.

In this sense, ambiguity is not always stabilizing. It can just as easily invite probing. The uncomfortable reality is that conventional deterrence demands a level of resolve that many policymakers are reluctant to acknowledge. Unlike nuclear weapons, whose very horror lends them a paradoxical clarity, conventional forces sit in a murkier space. They are more usable, but precisely for that reason, credibility hinges on demonstrated willingness.

A missile that will is restricted from use is not a deterrent. A submarine that will not be deployed into contested waters does not shape adversary behavior. A cyber capability that remains permanently in reserve does not impose costs. Deterrence, in the conventional domain, is performative. It must be signaled, exercised, and at times demonstrated.

This does not mean recklessness or a rush to escalation. It means recognizing that deterrence is not cost-free. If the objective is to prevent adversary action, then one must be prepared to act before the situation becomes intolerable. Waiting until costs are imposed on you, economically, militarily, or politically undermines the very logic of deterrence. This is where much of the current discourse falls short. There is a tendency to treat conventional capabilities as inherently stabilizing, as though their mere existence alters adversary calculations. But capabilities without credible intent are inert. Worse, they can create a false sense of security, masking the erosion of deterrence beneath a veneer of preparedness.

The challenge is particularly acute for middle powers like Australia, which rely heavily on alliances and extended deterrence. As questions grow around the credibility of U.S. nuclear guarantees, especially in a more contested and multipolar environment, there is an understandable desire to bolster national self-reliance through conventional means. This is a sensible objective. But it cannot be achieved through hardware alone.

If conventional forces are to serve as a substitute or even a supplement to nuclear deterrence, then they must be embedded within a clear framework of political resolve. This requires more than capability development. It requires declaratory policy, strategic signaling, and a willingness to accept escalation risks.

For example, if the laying of sea mines in Australian waters is deemed unacceptable, then that must be stated clearly and backed by a credible commitment to respond with force if necessary. Anything less invites incremental encroachment. Over time, such encroachment normalizes behaviors that would once have been considered intolerable.

History offers ample evidence of this dynamic. Deterrence erodes not in dramatic moments, but through a series of small, unchallenged actions that cumulatively shift the baseline of what is acceptable. By the time a clear red line is crossed, it is often too late as the adversary has already recalibrated expectations.

The solution is not to abandon conventional deterrence, but to take it seriously. This means confronting uncomfortable questions. Are we prepared to use long-range strike capabilities against an adversary’s military assets in the initial stages of a crisis? Would we target grey-zone actors operating below the threshold of armed conflict? How do we signal our intentions without triggering the very escalation we seek to avoid? There are no easy answers, but avoiding the questions altogether is not a strategy, it is an abdication.

Ultimately, deterrence is about shaping perceptions. It is about convincing an adversary that the costs of action will outweigh the benefits. This cannot be achieved through ambiguity alone, nor through capability acquisition in isolation. It requires a coherent integration of means, messaging, and above all else, will.

If policymakers are unwilling to countenance the use of conventional force, then they should be honest about the implications. In such a scenario, conventional capabilities do not replace nuclear deterrence; they merely decorate its absence.

The risk is not just strategic failure, but strategic surprise. An adversary that perceives a gap between capability and intent will exploit it; once that perception is formed, it is exceedingly difficult to reverse.

Deterrence, in the end, is a test of credibility and resolve. It is not measured by what you possess, but by what an adversary believes you will do. In strategic competition, credibility is not claimed; it is proven and without resolve, deterrence is nothing at all.

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.

Deterrence Without Resolve Is No Deterrence at All was originally published on Global Security Review.

The Indo-Pacific is entering a far more dangerous strategic era. Military modernization, grey-zone coercion, and rapid nuclear expansion are reshaping the regional balance of power. Most notably, China is undertaking a historic expansion of its nuclear arsenal, investing in silo fields, road-mobile intercontinental ballistic missiles, ballistic missile submarines, and dual-capable systems. Simultaneously, Russia’s willingness to use nuclear threats in Europe demonstrates that nuclear coercion is once again central to great-power competition.

In Washington, proposals such as Ely Ratner’s Pacific Defense Pact reflect recognition that the current security architecture is insufficient. A more formalized collective defense structure in the Indo-Pacific is necessary.

However, this is not sufficient. A conventional Pacific Defense Pact does not fully address the most dangerous level of escalation to large-scale conventional war or nuclear attack. What the region now requires is a narrowly defined Indo-Pacific nuclear alliance.

A Narrow, Explicit Purpose

This would not be a sweeping defense pact covering every maritime incident, border clash, cyber intrusion, or grey-zone coercive act. It would have a clear and carefully delimited purpose. That is to deter large-scale conventional war or nuclear attack against member states.

Its clarity would be its strength. That clarity performs a second vital function. It minimizes the risk of entrapment by ensuring member states are not dragged into escalation over actions below the threshold of war. By explicitly excluding grey-zone coercion and limited crises from its nuclear remit, the alliance would reassure leaders that only truly existential threats trigger its highest-level commitments.

Participation becomes politically sustainable and strategically credible because it avoids automatic escalation over incremental provocations. The alliance would draw a line at catastrophic strategic aggression.

The Historical Record: Why Nuclear Deterrence Matters

The case for a nuclear alliance is not theoretical. It is grounded in historical experience. During the Cold War, nuclear parity between the United States and the Soviet Union prevented direct large-scale war and nuclear attack in Europe. Despite ideological confrontation and proxy conflicts, neither side attempted a conventional war or nuclear attack on the other’s core territories. Nuclear weapons imposed restraint. They deterred not just nuclear use, but overwhelming conventional assault.

Similarly, within NATO, the presence of U.S. nuclear guarantees has prevented full-scale Russian conventional attack on Alliance territory. Moscow has tested boundaries through

hybrid tactics and coercive signaling, but it has not launched a large-scale attack on NATO soil. Nuclear deterrence at the alliance level raised the costs to an unacceptable threshold.

The 1969 Sino-Soviet border conflict further illustrates how nuclear capability constrains escalation. The Soviet Union’s nuclear superiority allowed it to signal credible threats, while China’s emerging nuclear capability and mobilization signaled resolve. Mutual fear of escalation compelled negotiation, including intervention through U.S. triangular diplomacy. Nuclear weapons shaped behaviors without being used.

The India–Pakistan experience is equally instructive. Prior to overt nuclearization, the two states fought multiple full-scale wars. Since their nuclear tests in 1998, crises have erupted, but they have remained limited. Missile strikes, cross-border skirmishes, and periods of great tension have not escalated into all-out conventional war or nuclear attack. Nuclear deterrence imposed a ceiling on the conflicts.

Contrast this with the Russia–Ukraine war. Ukraine relinquished its nuclear arsenal in the 1990s and now confronts a nuclear-armed Russia without possessing its own nuclear deterrent. The result has been a prolonged and costly conventional war of attrition. The absence of mutual nuclear deterrence has made sustained large-scale conventional war possible. By comparison, Russia has not launched a direct assault on NATO territory precisely because nuclear deterrence underwrites NATO’s collective defense.

The pattern is clear. Where credible nuclear deterrence exists between adversaries, large-scale conventional war and nuclear attack is sharply constrained or avoided. Where it does not, prolonged and devastating large-scale conventional war and nuclear attack becomes more likely.

The Indo-Pacific Strategic Gap

The Indo-Pacific currently relies on a patchwork of bilateral extended deterrence arrangements centered primarily on Washington. These remain essential, but they are increasingly strained or at risk of being fractured by China.

China’s expanding nuclear arsenal complicates escalation management. A larger and more survivable force reduces the credibility of assumptions that escalation will remain controlled or asymmetrical. Meanwhile, the region contains multiple flashpoints, including Taiwan, the South China Sea, the Korean Peninsula, and the India–China border where conventional conflict could rapidly climb the escalation ladder.

Frameworks like AUKUS and the Quad strengthen capabilities and coordination, while the proposed Pacific Defense Pact aims to guarantee that the U.S. and its allies can act in concert during crises or conflicts. But they are not structured as nuclear deterrence mechanisms. They do not institutionalize shared nuclear declaratory policy, crisis consultation at the strategic level, or joint planning for high-end escalation management. A nuclear alliance would fill that gap.

Beyond a Pacific Defense Pact

A Pacific Defense Pact, as envisioned in conventional terms, strengthens interoperability and signals unity. But without an explicit nuclear dimension, it leaves ambiguity at the highest rung of escalation. That ambiguity can invite miscalculation.

A nuclear alliance would not broaden commitments; it would sharpen them. It would: (1) establish shared declaratory policy on deterrence of large-scale war and nuclear attack, (2) institutionalize strategic consultation mechanisms during crises, (3) coordinate planning to ensure credible escalation management, and (4) reinforce extended deterrence while discouraging independent nuclear proliferation.

Importantly, such an alliance need not require additional states to acquire nuclear weapons. Like NATO, it could rely on extended deterrence commitments and nuclear-sharing with structured burden-sharing and planning arrangements. Nuclear forces may remain nationally controlled, but alliance cohesion amplifies deterrent credibility. 

Clarity as Stability

The objective is not confrontation. It is clarity. By defining a narrow and explicit threshold—large-scale conventional war or nuclear attack—the alliance reduces the risk of catastrophic miscalculation. It signals to potential aggressors that existential aggression will trigger unified strategic consequences.

Simultaneously, it reassures members that lower-level competition will not automatically escalate to nuclear commitments. This dual clarity strengthens deterrence at the top end and stabilizes politics at the lower end.

A Necessary Evolution

The Indo-Pacific is now the central arena of 21st-century strategic competition. Nuclear modernization is accelerating. Multi-nuclear dynamics are emerging. Escalation timelines are compressing.

History shows that nuclear weapons, and when embedded within credible alliance structures, deter catastrophic war. They prevent large-scale conventional war and nuclear attacks not because they are desirable tools of war, but because they impose unacceptable costs on those who contemplate it.

A Pacific Defense Pact is a step forward, but in the current strategic environment, it is not enough. To deter large-scale conventional war and nuclear attack in the Indo-Pacific, the region must move beyond a Pacific Defense Pact. It must build a nuclear alliance.

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: Why the Indo-Pacific Requires a Nuclear Alliance was originally published on Global Security Review.

This issue is not new. In his 1957 book Nuclear Weapons and Foreign Policy, Henry Kissinger made a controversial, yet analytically compelling, argument for the possible utility of tactical nuclear weapons in limited wars. He warned that massive retaliation was neither credible nor effective for deterring limited aggression and that a rigid dichotomy between conventional and strategic nuclear responses risked inviting coercion at the lower rungs of the escalation ladder. For Kissinger, introducing the possibility of limited nuclear use was not a call to war, but a recognition of strategic reality; the ability to escalate with restraint could deter adversaries from escalating first.

Fast forward to the 2030 scenarios modeled in Guardian Tiger I and II, and Kissinger’s insights remain disturbingly relevant. In the exercise, North Korea carried out a low-yield nuclear strike targeting South Korean naval vessels. American decision-makers, faced with the risk of horizontal escalation with China and the lack of consensus among allies, struggled to identify a proportional yet credible response. The idea of a retaliatory tactical nuclear strike was floated, but the simulated American leadership hesitated, reflecting both doctrinal ambiguity and an operational gap in American nuclear capabilities.

The risks of such hesitation are manifold. First, American restraint may be misinterpreted as indecision or weakness, particularly by allies like South Korea and Japan, who are directly exposed to North Korean and Chinese threats. Second, it creates an opening for adversaries to believe they can escalate to the nuclear level without inviting proportional retaliation. Third, it undermines the entire architecture of extended deterrence that underpins regional security.

Critics will rightly point out the perils of normalizing nuclear use. Introducing tactical nuclear weapons into a conflict zone invites moral hazards, increases the risk of miscalculation, and breaks long-standing nuclear taboos. It also challenges existing declaratory policies, such as the 2022 P5 Joint Statement affirming that “a nuclear war cannot be won and must never be fought.”

But these arguments, while valid in principle, must be weighed against the operational reality that a low-yield nuclear strike by an adversary may not be deterred by threats of massive retaliation. As the Atlantic Council report noted, North Korea’s nuclear doctrine increasingly incorporates elements of pre-delegated authority, tactical nuclear use, and efforts toward a more survivable second-strike posture. If the United States signals that it will not respond proportionally to a limited nuclear attack, North Korea may calculate that it can use nuclear weapons to coerce the South or constrain American action without triggering regime-ending consequences.

Moreover, the credibility problem is not confined to North Korea. China, observing Washington’s reluctance to respond in kind, may also be emboldened to engage in horizontal escalation, confident that the United States’s nuclear threshold is politically—and perhaps operationally—immobile. This perception could unravel the strategic coherence of integrated deterrence.

To address these challenges, US Forces Korea (USFK) and Indo-Pacific Command should adopt a more robust approach across multiple dimensions. First, the United States should consider forward-deploying platforms capable of delivering low-yield nuclear weapons. This could include the reintroduction of dual-capable aircraft or sea-based assets positioned in or near the Korean Peninsula. Such deployments must be both survivable and possess the ability to clearly signal an adversary of will, while being fully integrated into bilateral operational planning with the Republic of Korea (ROK).

Second, escalation options must be clarified through updates to American declaratory policy. This does not mean issuing public ultimatums or fixed thresholds but rather ensuring that adversaries understand the United States is willing to conduct proportional nuclear responses if deterrence fails. Strategic ambiguity must not become strategic paralysis.

Third, while the US and South Korea launched the Nuclear Consultative Group (NCG) in 2023 to enhance extended deterrence coordination, further institutionalization is needed. A structure modeled more closely on the North Atlantic Treaty Organization’s (NATO) Nuclear Planning Group would help deepen transparency, signal unity of purpose, and reduce the risk of fragmented responses during crises.

Fourth, both US and ROK forces must be equipped and trained to operate in the aftermath of a limited nuclear strike. This includes rehearsals and exercises focused on base survivability, radiological detection and decontamination, logistics continuity, and the resilience of command-and-control (C2) systems.

Fifth, strategic communication must be strengthened. Clear and consistent messaging to both adversaries and allies is critical. Deterrence depends not only on military capabilities, but also on the perceived credibility of those capabilities and the intentions behind them.

Ultimately, the goal of these measures is not to normalize the use of nuclear weapons, but to reinforce the threshold against their use by making deterrence more credible and responsive.

If that threshold is ever crossed and the United States fails to respond proportionately, the credibility of its extended deterrence architecture could unravel. The Guardian Tiger exercises highlight this grim possibility and should serve as a clarion call to action for policy and defense leaders alike.

As Kissinger warned in 1957, the danger of total war arises not so much from a deliberate decision to embark on it as from a series of actions which, though rational in themselves, cumulatively lead to disaster. The United States must ensure that its rational desire to avoid nuclear escalation does not lead to an irrational loss of deterrence. Tactical nuclear flexibility, responsibly exercised and credibly signaled, may be the painful but necessary insurance policy to uphold peace in East Asia.

Dr. Ju Hyung Kim, President of the Security Management Institute, a defense think tank affiliated with the South Korean National Assembly, is currently adapting his doctoral dissertation, “Japan’s Security Contribution to South Korea, 1950 to 2023,” into a book.

The Case for US Low-Yield Nuclear Options in Korea was originally published on Global Security Review.