In February 2026, more than 200 personnel from Australia, the United Kingdom, and the United States gathered on Australia’s east coast for the latest AUKUS Maritime Big Play exercise, where operators tested roughly thirty next-generation autonomous capabilities, including a live strike by a one-way attack munition. Earlier iterations of the series had already demonstrated something more consequential than any single platform: the ability of the three navies to control autonomous assets belonging to one another. Allied autonomy has moved out of the laboratory and into operational formations, and it is moving faster than the alliance frameworks that govern who may authorize a machine to act. 

The Seam in the Umbrella 

Extended deterrence has always rested on shared expectations about decision-making. The United States and Japan formalized this in December 2024, when the two governments issued their first Guidelines for Extended Deterrence, reinforcing consultation and communication procedures for the gravest decisions the alliance could face. Consultation procedures of this kind assume that the decisions in question move at human speed, through ministers and commanders who can meet, confer, and align. Autonomous systems introduce a class of alliance decisions that will not wait for a meeting. 

Every ally that fields autonomous systems encodes national rules about when a machine may engage, when it must ask a human, and when it must stop. The United States codifies its approach in Department of Defense Directive 3000.09, which sets rigorous verification, testing, and senior-review requirements designed to minimize unintended engagements. Allies maintain their own rules, shaped by their own laws, doctrines, and political constraints. 

Those national rule sets do not automatically align, and in a combined force the differences become seams. A coalition formation may contain systems that would engage a given contact under one national authority profile and hold fire under another. Adversaries study seams. 

The probing will not be hypothetical. China has spent more than a decade practicing pressure beneath the threshold of armed conflict, from maritime militia swarms to coercive air intercepts, precisely because ambiguity about an alliance response is exploitable. Russia has run the same playbook against NATO members in the air and undersea domains. A coalition whose autonomous systems answer that pressure under visibly different national rules hands its adversaries a map of where the alliance hesitates. 

The consequences for deterrence are direct. The most immediate risk is entrapment at machine speed: when an allied autonomous system engages inside the American security umbrella, the United States can inherit an escalation decision it never made, at a pace that forecloses the consultation the alliance promised itself. Mismatched authority thresholds also invite probing, because an adversary can calibrate provocations that one member’s systems would answer and another member’s system would not, and can harvest knowledge of alliance rules from the pattern of responses. 

Assurance suffers as well. An alliance that cannot state clearly how its machines hold fire loses precision in its guarantees at exactly the moment allies under threat are asking for more precision, not less. Credibility in the machine age includes the credibility of restraint. 

Authority Interoperability 

The building blocks for closing the seam already exist. Directive 3000.09 gives the United States a mature national template. The Five Eyes cybersecurity agencies showed in May 2026 that allied governments can speak with one voice on machine autonomy when they jointly published guidance on agentic artificial intelligence, urging organizations to prioritize “resilience, reversibility and risk containment over efficiency gains.” The Maritime Big Play program has likewise turned toward shared command-and-control software and a common autonomous baseline across the three AUKUS navies. Each of these efforts is necessary. What none of them yet delivers is the specific artifact extended deterrence requires: a legible statement of each ally’s engagement authority rules that coalition systems and coalition commanders can rely on before they operate together. 

Allied autonomy needs authority interoperability, built as deliberately as data interoperability was built over the past three decades. Three practical steps would supplement the work already underway. Allies could publish national authority profiles, meaning standardized declarations of the engagement tiers their systems may exercise, the conditions that trigger human review, and the recall mechanisms that stop a pending action. Combined forces could adopt shared reversion standards, so that any coalition system can be halted through a common, tested procedure regardless of which flag it flies. Extended deterrence consultations, on the model the United States and Japan set in 2024, could add an autonomy annex that establishes in advance how allied autonomous engagements inside the umbrella will be communicated, reviewed, and, where necessary, walked back. 

These steps ask allies to formalize what alliance staffs already negotiate informally under time pressure. Deterrence theory has long held that credibility rests on capability and will. Combined autonomy adds a third term: legibility. An alliance whose machines carry legible, compatible, and reversible authority is an alliance an adversary cannot divide at the seam. Extended deterrence in the machine age will belong to the alliances that make their authority architecture as interoperable as their ammunition. 

Burak Oktenli is an independent researcher in Washington, DC, conducting research on human-machine authority architecture and the governance of autonomous military systems. He is the author of the ten-volume Authority and Architecture series on the governance of autonomous decision authority, and his analysis has appeared in RealClearDefense, Task and Purpose, and The Space Review. Views expressed in this article are the author’s own. 

Allied Autonomy Is Creating a New Seam in Extended Deterrence 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.

After World War II, both Japan and Germany became allies of the United States while the Soviet Union became a serious enemy. Most importantly, the Soviet Union established in Eastern Europe an alliance of nations under the Warsaw Pact. Thus, a decades-long Cold War began.

It was widely assumed that the collapse of the Soviet Union heralded an era of global cooperation and the end of great power competition and conflict. Arms control brought about the Intermediate Nuclear Forces Treaty (INF), Strategic Arms Reduction Treaty (START I and II) and the Conventional Forces in Europe Treaty (CFE) agreements.

Today, however, as many military and diplomatic experts conclude, the dangers facing the United States and its allies are more complex and more serious than perhaps at any time since the end of WWII. Now, more than ever, arms control remains elusive.

Nuclear conflicts are now among the most serious potential dangers, including proliferation of nuclear weapons, the pending end to formal strategic arms limits, and the actual use of theater nuclear force arising out of existing conventional conflicts.

To lessen such dangers, nuclear abolitionists proffer numerous arms control proposals. Six ideas are most common: (1) a policy of no first use of nuclear weapons; (2) adoption of a “minimum deterrent” nuclear strategy; (3) the elimination of intercontinental ballistic missiles (ICBMs); (4) a unilateral freeze of US nuclear force development; (5) an extension of New START nuclear arms limits; and (6) abandonment of any new theater nuclear forces such as the nuclear sea-launched cruise missile (SLCM-N) or the sea-launched cruise missile. All of these strategies harm American and allied security and make worse the strategic nuclear balance.

The US extended deterrent has, for 70 years, rested on the option of using nuclear force to stop massive conventional attacks on US forces and allies overseas. Depending on the regional military balance, such nuclear extended deterrent options were, and remain, viewed by our allies as central to keeping their nation safe from Soviet/Russian and Chinese aggression.

Minimum deterrence strategies assume the only retaliatory targets the US needs to hold at risk are adversary cities where a few hundred nuclear warheads are all that is needed to deter. This doctrine assumes Russia and China will be completely deterred by the fear of losing large numbers of their civilian population. But this ignores the fact that these regimes murdered millions of their own people to gain power—showing little value for human life. Even worse, a minimum deterrence strategy would also leave alive the leaders of such nations as well as their nuclear and conventional forces with which they will commit aggression.

Cutting out the land-based ICBM force and a third of the ballistic missile submarine force would unilaterally reduce the US strategic nuclear force to around 500 at-sea on-alert warheads. This would be only a third of the allowed New START treaty force and give an 8 to 1 to 18 to 1 Russian and Chinese advantage in nuclear weapons, respectively. This would ensure that both nations frequently use nuclear weapons for coercion and blackmail.

A freeze on American nuclear force development would be a deterrence disaster. The US has not yet fielded any portion of the modernized triad, which is not rusting into obsolescence. Russia has completed over 90 percent of its own modernization and China is well on its way to tripling the size of its nuclear force over the next decade. Neither would participate in a unilateral freeze. Again, the United States would face a far superior adversary.

An extension of New START sounds attractive but would be harmful to American interests. It would delay any needed uploading of American warheads. It would not affect or make transparent China’s breathtaking nuclear build-up. And without a sea change in Russian behavior, verifying current arms limits would still be impossible, given the past five years of treaty violations by Moscow.

The Congressional Strategic Posture Commission report of October 2023 emphasized the urgency of rebalancing the current gap in US regional nuclear forces. The SLCM-N and better theater air deterrence were key recommended upgrades, both of which would be eliminated by a number of these proposals. It is precisely this deterrence gap which Moscow has leveraged to limit US and allied assistance to Ukraine.

The restraint these arms control ideas wish upon the US military assumes that Russia and China will reciprocate. But in the multiple decades after the end of the Soviet Union, massive US restraint was eventually met with what Admiral Richard has described as a “breathtaking” Chinese build-up and a near matching Russian modernization. As former Secretary of Defense Harold Brown once warned, “We build, they build. We stop; they build.”

Now is the time to reject nuclear abolition for what it is, a purposeful effort to weaken the United States. American lives and freedom depend on it.

Peter Huessy is Senior Fellow at the National Institute for Deterrence Studies. Views expressed are his own. 

Making Nuclear Blackmail Great Again was originally published on Global Security Review.

Prior to Russia’s invasion of Ukraine, Germany was one of Russia’s closest economic partners. At the outset of the war, Germany was criticized for its hesitant offer to Ukraine of 5,000 military helmets, at a time when other European states, especially the Baltic nations, were offering weapons and heavy military equipment to defend against the Russian invasion.

This hesitancy had two facets. First, the belief that military aid would escalate the war to unmanageable levels. Second, the fear that Russia could easily achieve its military objectives. In such a case, it was unwise for Germany to risk its economic interests, particularly its heavy reliance on Russian natural gas.

However, Germany, later, began supplying weapons and other military aid to Ukraine under domestic and international pressures. Later, Germany even supplied heavy military equipment to Ukraine. As of August 2025, Germany is one of the largest suppliers of military aid, amounting to $47 billion worth. This includes air-defense systems, advanced drones, and heavy artillery. German action illustrates how incremental support erodes Russia’s nuclear red lines.

Incremental Steps Eroding the Threshold 

In the Russian conceptualization of deterrence, strategic deterrence (strategicheskoye sderzhivaniye), both nuclear and conventional deterrence merge into one holistically integrated framework. The threat of or actual use of nuclear weapons would deter a conventional attack on Russia, help achieve military objectives, prevent third parties from entering a war, and help de-escalate a war. In the 1990s, when Russia fielded a conventionally inferior armed force, it relied primarily on nuclear deterrence for its security.

However, a nuclear-deterrence-focused security strategy does not consider the erosion of thresholds owing to incremental changes during war (i.e., incremental changes test interwar and intrawar deterrence). After Pakistan became a nuclear power, Pakistan employed sub-threshold tactics (terrorism) against India, assuming that the fear of mutual nuclear vulnerability would prevent India from using kinetic means in retaliation. However, this approach failed when India employed conventional force against Pakistan in 2016, 2019, and, more prominently, in Operation Sindoor (2025). Similarly, Ukraine challenged Russia with its aggressive attacks in response to Russian invasion.

Russia’s updated nuclear doctrine (2024) brought the threshold of nuclear employment to an even lower level than earlier doctrine. This includes “actions by an adversary affecting elements of critically important state or military infrastructure” and “the massive launch […] of air and space attacks means (strategic and tactical aircraft, cruise missiles, unmanned, hypersonic and other aerial vehicles).”

Ukraine’s Operation Spyder Web crossed these “nuclear thresholds” set in the 2024 doctrine. Russia’s numerous threats of tactical nuclear weapons use are not taken seriously by Europe any longer. This creates a stability-instability paradox where “conventional balances also reduce the credibility of nuclear threats precisely because there is a conventional alternative to resorting to nuclear weapons.”

One of the implications of the stability-instability paradox in international relations is that while nuclear weapons create stability at the strategic level by deterring large-scale war between nuclear-armed states, they increase the likelihood of smaller, limited, or conventional conflicts. This is reinforced in the Ukraine conflict, where Russia simply cannot use nuclear weapons to deter third-party military help to Ukraine and Ukraine’s counteroffensives.

Nuclear deterrence has limitations and does not deter incremental or conventional actions of lower yields. The costs associated with utilizing nuclear weapons for deterring incremental erosion of thresholds is unimaginable. It is difficult for parties in a war to agree upon thresholds. Thus, resorting to conventional attacks rather than escalating to nuclear use becomes more likely, even after crossing stated red lines. 

States Should Build on That 

For that matter, those states looking to augment their defence preparedness should invest in conventional deterrence capabilities that can guarantee security. This goes beyond just building missile and air-defense systems of a high calibre. Conventional deterrence is not merely about weapons to deter an adversary.

Military thinking needs to go beyond just inventing new weapons and focus on military strategy. States need to go beyond a one-size-fits-all understanding of deterrence, where all states subscribe to the same benchmarks, variables, and conceptualization of deterrence, and have a shared sense of it. Situating deterrence within the fold of strategic culture, how a state’s strategic culture shapes deterrence, is more helpful. For instance, in contrast to the denial versus punishment typology, Russia uses the forceful versus non-forceful scheme for deterrence.

States may need to invest in the re-invention of military doctrines, strategy, and thinking to suit current challenges. It is worth studying how adversaries see the concept of deterrence. It confers two advantages. First, it helps one remain prepared for any incremental utilization of force under the fear of mutual destruction. Second, it allows the defender to assess the opponent’s risk-taking appetite and nuclear threshold in a war. This would confer advantages associated with effectively using conventional means.

At the same time, both parties need to be aware of over-extension, where a misguided action can cause a catastrophic nuclear exchange. Since agreeing on the same trigger point is subjective and difficult, states must study the pace, timing, and intensity of the use of non-nuclear forces to effectively achieve objectives without jumping to the nuclear step on an escalatory ladder.

In the end, preventing nuclear war is critical. Thus, understanding thresholds is important. If war is unlikely to end, ensuring it does not escalate to nuclear use should be a top priority.

Anshu Kumar is a Junior Research Fellow at the Centre for Russian & Central Asian Studies, Jawaharlal Nehru University, New Delhi.

The Russia-Ukraine Conflict Showcases the Limits of Nuclear Deterrence was originally published on Global Security Review.

A decade ago, Paul Bracken warned of such possibilities in his book, The Second Nuclear Age. Because deterrence theory went out of vogue for so long in the West, analysts are now woefully unprepared to think about these challenges and their implications. Today, all possible threats to our Western notions of peace and stability have been jumbled into one giant intellectual recycling bin of deterrence theory. It is time to talk much more seriously about (1) the role of nuclear weapons in deterrence and (2) the role of nuclear deterrence in a new era of nuclear disorder in the Asia-Pacific.

Nuclear weapons play a unique and unprecedented role in how nations think about geopolitical order. They have fundamentally altered how countries think about alliances and the nature of international order. William Walker wrote about the establishment, in the late 1960s, of a nuclear order based on managed systems of deterrence and abstinence. The former was a system “whereby a recognized set of states would continue using nuclear weapons to prevent war and maintain stability, but in a manner that was increasingly controlled and rule-bound,” and in which there was a degree of familiarity in essentially dyadic deterrence relationships.

Nuclear abstinence consisted of a system “whereby other states give up sovereign rights to develop, hold, and use such weapons in return for economic, security, and other benefits,” concomitantly with the provision of nuclear umbrellas and a stable Nuclear Non-proliferation Treaty (NPT). It is a system whereby not only the possession, but also the use of nuclear weapons is controlled. According to Walker, the stability and robustness of these two systems would provide the rationale for many states in the international system to abstain from acquiring weapons and for states to rely on the US for their national survival.

There are several elements that gradually developed after the second world war that characterized this nuclear order—dissuading countries from developing nuclear weapons. First, the number of nuclear weapon states is relatively small. Second, nuclear weapons are no longer considered merely bigger and better conventional weapons. Third, there are strong norms against possession and the use of nuclear weapons. Fourth, there are no direct and immediate military threats to US allies. Fifth, war between major powers is relatively unlikely.

This and the prospects for nuclear proliferation are relatively limited. The Nuclear Non-proliferation Treaty (NPT) proposed in the late 1960s eventually attract more and more states, thus contributing to a norm against nuclear proliferation. It also contributed to nuclear and conventional arms control as concepts and policies in the international community. The world was able to more easily navigate crises and confrontations as thinking evolved about strategic theory and concepts and their application to real world politics and diplomacy.

The international (nuclear) order held together. It is now slowly eroding. China is modernizing its conventional and nuclear forces, all while growing increasingly bellicose and regularly threatening to invade Taiwan.

Russia annexed Crimea in 2014. The West did nothing and never imagined this would be followed by a full-scale invasion eight years later—with regular Russian threats to use nuclear weapons.

Now, Australian academic Peter Layton is writing about “this nuclear threat business.” Until recently, this behavior was reserved for rogue states like North Korea. Such behavior was beneath great powers such as Russia and the United States. Not only does the West have to think about deterrence in a multipolar setting, but it must face nuclear dictators.

Nuclear arsenals in Asia are also expanding. From China’s rapid nuclear expansion to questions about the future of Pakistan’s nuclear posture, the future is uncertain. There are renewed questions about the future of South Korea and nuclear weapons.

Arms control is also breaking down. Much to the chagrin of arms control careerists, who argue for unilateral, bilateral, and trilateral nuclear arms control as a public good sui generis, arms control is not carrying the day. Bereft of the intellectual foundations of deterrence that guided impressive negotiations in SALT I and II, and even START I, discussing nuclear strategy is now taboo in the West.

The nuclear order that existed during the Cold War and the post–Cold War peace dividend, especially in the Asia-Pacific, is eroding rapidly. For many nuclear historians, this trend is not new. Now is the time to grieve the loss of the utopian dream and think seriously about how to navigate this new era of disorder and the role of nuclear weapons in deterring war and promoting peace.

Christine Leah, PhD, is a Fellow at the National Institute for Deterrence Studies. Views expressed in this article are the author’s own. 

Nuclear Order and Disorder in the Asia-Pacific was originally published on Global Security Review.