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.

For advocates of renewed nuclear weapons testing, stop packing for the journey to the Nevada National Security Sites (NNSS). No mushroom cloud or subterranean detonation is soon to take place. Anti-nuclear protestors should also stay home.

The truth is less exciting. No real changes will happen “immediately” that “light up the sky and shake the ground.” This is not to say that the announcement had no effect. In fact, the statement was indeed monumental and incredibly significant.

Contrary to public perception, the US has never ceased testing its nuclear weapon systems. What has changed since the 1992 self-imposed moratorium on high-yield explosive testing is the nature of those tests.

Before 1992, the US conducted 1,054 nuclear weapon test explosions. The country detonated 839 of those warheads underground, mostly at the then-named Nevada Test Site, where the last halted test, Icecap, still stands as a memorial to the explosive testing days.

Several scientists involved in Icecap acknowledge that, owing to the extensive preparations undertaken, such as instrumentation, computational simulation, analysis, and test rigging, the most significant insights were gained from the limited number of unsuccessful tests. In other words, there is still great confidence in the performance and reliability of the American nuclear arsenal. It is this kind of “testing” to which President Trump’s declaration is likely referring.

Since 1992, testing has been through proxy systems that simulate a nuclear explosion’s unique energy output and then uses the results to validate physics models on advanced computer systems, known as physics-based modeling. This approach provides a way to validate the physics and predict the performance of a nuclear explosion under conditions that were never known in an underground test.

Scientists continuously conduct these tests, improving and refining them as added details are learned. They often report that scientists know much more now than possible from explosive testing.

Despite the president’s directive that testing “will begin immediately,” experts agree that resuming full-scale nuclear explosive testing is a complex and time-consuming endeavor. According to the Arms Control Association, it would take at least 36 months to prepare the Nevada Test Site for contained underground detonations.

This includes environmental assessments, infrastructure upgrades, and political approvals. This does not mean that explosive testing is impossible, but it represents a clear change in policy and a national effort to move nuclear weapons to the forefront of national strategy through an active nuclear explosive testing program.

The phrase “on an equal basis” is particularly provocative. It implies that nations like Russia and China may already be conducting nuclear explosive tests or at least advancing their capabilities in ways that challenge the spirit of the Comprehensive Nuclear Test Ban Treaty (CTBT). Either of these should sound alarms and rightly must elicit a response.

The president has chosen precisely the response as outlined in the National Institute for Deterrence Studies’ (NIDS) Dynamic Parity report, where a response matches the activities of adversaries, giving them the option to continue expanding their nuclear capabilities, knowing how America will respond, or cease and return to the table to negotiate for a more stable relationship.

The announcement of an “immediate” resumption of (explosive) testing is monumental because of its effect on deterrence. In his international policy book, The Necessity of Choice, Henry Kissinger writes that deterrence is the (mathematical) product of will and capability. Few would question that the US has a nuclear arsenal and delivery systems that can cause incredible damage and harm. However, there is growing criticism and concern that the US lacks resolve to deploy its nuclear weapons even if an existential crisis arises.

Without clear signals of resolve, adversaries may doubt American willingness to act, weakening deterrence. This declaration supports that resolve without making a direct threat to any adversary. It simply puts them on notice.

Whether President Trump’s message leads to actual detonations or remains symbolic, it marks a turning point in American nuclear policy. It also aligns with the Dynamic Parity framework advocated by Curtis McGiffin and Adam Lowther, which calls for symmetrical deterrence and strategic clarity.

President Trump is demonstrating resolve, assuring allies, and highlighting American commitment to nuclear deterrence. The path forward should prioritize modernization, transparency, and diplomacy—not a return to the destructive rituals of past decades.

James C. Petrosky, PhD, is the President and Co-founder of the National Institute for Deterrence Studies and Professor Emeritus of the Air Force Institute of Technology. Views expressed in this article are the authors own. 

“Resumption of Nuclear Testing”—Not So Fast! was originally published on Global Security Review.