NATO’s recent establishment of Baltic Sentry (2025), Eastern Sentry (2025), and Arctic Sentry (2026) reflects more than a response to Russian aggression. Collectively, these operations demonstrate how modern deterrence has evolved to address persistent airspace violations, hybrid warfare, cyber-attacks, sabotage of critical infrastructure, and grey-zone coercion. While these missions are conventional military operations, they derive their strategic credibility from something far more significant, NATO’s integrated nuclear deterrence architecture.

This distinction is critical. NATO’s Sentry operations are not isolated military activities; they are conducted within an alliance whose conventional forces are underwritten by the collective nuclear capabilities of the United States, the United Kingdom, and France. Any adversary contemplating escalation understands that conventional confrontation with NATO carries the inherent risk of nuclear escalation. This integration between conventional and nuclear deterrence has underpinned Euro-Atlantic security for more than seventy years.

For the Indo-Pacific, the lesson is clear. As China rapidly expands its nuclear arsenal, North Korea continues to develop increasingly sophisticated nuclear and missile capabilities, and Russia under Vladimir Putin has revived Cold War-era nuclear coercion, regional allies cannot assume that conventional military cooperation alone will provide credible deterrence. If deterrence is to succeed, it must be built upon a coherent nuclear alliance before a crisis emerges, not after deterrence has already failed.

Conventional Operations Backed by Nuclear Deterrence

The strategic significance of NATO’s Sentry operations lies not simply in what they do, but in what stands behind them. Baltic Sentry enhances surveillance and protection of undersea communications cables, energy infrastructure, and maritime approaches following repeated acts of sabotage and suspicious activity in the Baltic Sea. Eastern Sentry reinforces NATO’s eastern flank through enhanced air policing, intelligence sharing, and rapid response capabilities in the face of persistent Russian military activity. Arctic Sentry reflects NATO’s growing focus on the High North as Russia and China expand their military presence in an increasingly contested region.

These operations improve situational awareness, interoperability, and alliance readiness. Yet none of them exist in isolation. Their credibility stems from NATO’s integrated command structure, collective defense commitments under Article 5 of the North Atlantic Treaty, shared military planning, and, fundamentally, the Alliance’s nuclear deterrence posture. NATO’s Nuclear Planning Group, alongside the independent nuclear forces of the United Kingdom and France and the United States extended nuclear deterrence commitments, ensures that any conventional confrontation carries strategic consequences far beyond the immediate theater.

This layered approach to deterrence is central to NATO’s success. Conventional operations deter day-to-day coercion, while nuclear deterrence prevents adversaries from believing they can escalate a conventional conflict without unacceptable consequences. The two cannot be separated; together they create a coherent deterrence architecture.

The Indo-Pacific’s Strategic Environment Has Changed

The Indo-Pacific now faces a security environment increasingly defined by nuclear competition. China’s rapid expansion and modernization of its nuclear arsenal is reshaping the regional balance of power. At the same time, Beijing continues to employ sustained grey-zone coercion through military pressure around Taiwan, coercive operations in the South China Sea, cyber campaigns, and increasingly frequent air and maritime incursions directed at neighboring states.

North Korea’s advancing nuclear weapons and ballistic missile programs add another layer of strategic complexity. Pyongyang’s continued weapons development increases the likelihood that any regional crisis could involve nuclear coercion or escalation.

Meanwhile, Russia’s full-scale invasion of Ukraine has demonstrated that nuclear weapons remain central to great-power competition. Throughout the conflict, President Vladimir Putin has repeatedly employed nuclear rhetoric and strategic signaling to deter Western intervention. The assumption that the end of the Cold War marked the end of nuclear coercion has proven false.

For Indo-Pacific allies, this means they are confronting not one, but three nuclear-armed challengers whose strategic interests increasingly overlap. Yet the region’s security architecture remains fragmented.

The Missing Foundation

The United States maintains strong bilateral alliances with Australia, Japan, South Korea, and the Philippines. Regional initiatives such as AUKUS and the Quad have strengthened defense cooperation, technological collaboration, and strategic coordination. These arrangements make important contributions to regional security.

However, they do not constitute an integrated alliance comparable to NATO. They lack common command arrangements, formalized collective defense obligations across the region, institutionalized nuclear consultation mechanisms, and a unified framework for integrating conventional and nuclear deterrence. This matters because conventional military cooperation alone cannot provide fully credible deterrence against nuclear-armed adversaries. NATO’s experience demonstrates that conventional operations derive their strategic weight from the knowledge that they are backed by a credible and integrated nuclear alliance. Without that strategic foundation, conventional activities risk being viewed as isolated demonstrations of resolve rather than components of a comprehensive deterrence posture. The Indo-Pacific is therefore attempting to strengthen conventional deterrence without first establishing the alliance architecture that gives such deterrence its greatest credibility.

Building Deterrence Before Crisis

History consistently demonstrates that alliances formed during conflict rarely prevent that conflict. They manage its consequences instead. Europe’s recent experience illustrates this lesson. Many of NATO’s most significant reforms, including enhanced forward deployments,

strengthened infrastructure protection, expanded readiness, and the establishment of the Sentry operations, were accelerated in response to deteriorating security conditions following Russia’s aggression against Ukraine. They represent adaptation after strategic warning signs became impossible to ignore.

The Indo-Pacific still has an opportunity to act before reaching a comparable point. Rather than waiting for a crisis over Taiwan, the South China Sea, or the Korean Peninsula to force hurried institutional change, regional democracies should begin developing the alliance structures necessary to sustain credible deterrence.

Such an alliance would not require every member to possess nuclear weapons. Instead, it would integrate conventional planning with extended nuclear deterrence, establish mechanisms for strategic consultation, coordinate contingency planning, strengthen interoperability, and ensure that regional conventional operations are supported by a credible nuclear deterrent capable of deterring nuclear-armed adversaries.

Conclusion

NATO’s Baltic Sentry, Eastern Sentry, and Arctic Sentry operations are not simply conventional military initiatives. They are visible expressions of a much deeper strategic reality: conventional deterrence is most credible when backed by an integrated nuclear alliance. Their effectiveness rests not only on ships, aircraft, and surveillance systems, but on the certainty that any attempt to escalate against NATO would confront the Alliance’s collective nuclear deterrent.

The Indo-Pacific faces an increasingly dangerous strategic environment characterized by a rapidly expanding Chinese nuclear arsenal, an emboldened North Korea, and a resurgent Russia that has returned nuclear coercion to the center of international politics. In such an environment, conventional cooperation alone is unlikely to provide sufficient deterrence.

The central lesson from NATO’s Sentry operations is therefore not that the Indo-Pacific should simply replicate these missions. It is that such operations derive their credibility from the nuclear alliance that stands behind them. Waiting to build that alliance until deterrence has failed would repeat the strategic mistakes history has repeatedly exposed. The time to establish an integrated Indo-Pacific nuclear alliance is before a crisis begins, not after conflict has already become unavoidable.

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

NATO’s Sentry Operations Show Why the Indo-Pacific Needs a Nuclear Alliance was originally published on Global Security Review.

While certification is contingent on the US Navy’s ability to maintain its own submarine production rate, which is struggling to meet the planned two Virginia-class submarines per year, Australia would benefit greatly from their acquisition. Overall, it is worth noting that AUKUS Pillar I and Pillar II are likely to significantly enhance US undersea capabilities in the long term. Pillar I includes the rotational presence of one UK Astute-class submarine and up to four US Virginia-class submarines at HMAS Stirling, Western Australia, from 2027. HMAS Stirling provides the United States with greater access for the forward presence of nuclear-powered submarines in the Indo-Pacific.

Indo-Pacific access is further expanded via the new submarine base that is planned for the east coast of Australia by 2043. The authorized consolidated Commonwealth-owned Defence Precinct at Western Australia’s Henderson shipyard will provide contingency-docking and depot-level maintenance for AUKUS submarines by 2033, potentially alleviating some of the burden on US-based maintenance facilities. Pillar II will provide the advanced technology necessary to enhance US, UK, and Australian undersea capabilities, particularly for longer term advantages in mobility, survivability, lethality, and sustainability of allied forces.

Conversely, the SLCM-N is likely a significant factor in retaining American undersea capabilities. The SLCM-N will provide the US with flexible deterrence options in austere Euro-Atlantic and Indo-Pacific theatres, particularly as the US needs to provide extended nuclear deterrence to 32 NATO allies plus Australia, Japan, and South Korea. There are three options to consider when attempting to deter China, North Korea, and Russia.

First, the United States can provide Australia three to five conventionally armed Virginia-class submarines. This option is likely to significantly degrade American undersea capabilities through a lack of flexible response options for strategic deterrence and extended nuclear deterrence. Plus, Australia will need to manage three classes of submarines: the Collins-class, the AUKUS-class, and the SSN-AUKUS under this option.

Second, Australia can field a dual-capable submarines (DCS) mission for Australian Virginia-class submarines. This option requires the establishment of a nuclear planning group (NPG) to plan for a DCS mission for Australian Virginia-class submarines. These submarines would be capable of carrying the SLCM-N. This nuclear-armed option is unlikely to degrade US undersea capabilities, as Australia could support some US missions in the Indo-Pacific and provide flexible deterrence options. Australia will still need to manage three submarine classes under this option.

Third, the United States does not sell Virginia-class submarines to Australia, but instead bases submarines armed with SLCM-N in Australia, either on a permanent or rotational basis. This option does not degrade US undersea capabilities. However, under this option Australia should negotiate for extended nuclear deterrence guarantees. This option is not the end of AUKUS, but Australia will need to build sovereign SSN-AUKUS submarines to fill the gap left by Australia’s aging Collins-class submarines when they are retired.

Policymakers should not be afraid to consider a flexible nuclear-armed option in light of recent and historic Russian and Chinese rhetoric on AUKUS, especially when this rhetoric concerns “non-nuclear long-range precision strike capability.” Having a nuclear-armed option would provide enough flexibility to backstop and limit conventional war.

On April 18, 2025, Russia’s envoy to Indonesia, Sergei Tolchenov, defended military ties with Jakarta and did not deny claims that Russia seeks to station long-range military aircraft at the Manuhua Air Force Base at Biak Numfor, about 1400 kilometers north of Darwin, Australia. Russia asserted that AUKUS is more of a threat to the Asia-Pacific than Russian ties with Indonesia, which are “not aimed against any third countries and poses no threat to security in the Asia-Pacific region.” Tolchenov added that challenges to regional stability

are more likely to arise from the rotational deployment of large military contingents from extra-regional states on Australian territory, including the provision of airfields for the landing of strategic bombers and port infrastructure for visits by nuclear-powered submarines. Particularly alarming are the currently discussed plans to deploy the US intermediate-range missiles in Australia, which would put ASEAN [Association of Southeast Asian Nations] countries, including Indonesia, within its range, as well as the acquisition by the Royal Australian Navy of nuclear-powered submarines under the AUKUS trilateral partnership.

These comments are consistent with Putin’s rhetoric against the North Atlantic Treaty Organization (NATO).

This is not the first time Russia and China accused the US, UK, and Australia of risking an intensified arms race and military confrontation in the Indo-Pacific. A report by the China Arms Control and Disarmament Association, China Nuclear Strategic Planning Research Institute, and the Russian Energy and Security Research Centre stated, “non-nuclear long-range precision strike capability, being provided to Australia, will affect nuclear deterrence and strategic stability.” The report goes on to say that “[w]hile current non-nuclear strategic weapons cannot carry out all the missions assigned to nuclear weapons those still can produce strategic effects.” The report further criticizes AUKUS’ nuclear submarine cooperation, which the report suggests will trigger a regional submarine arms race.

Chinese and Russian threats should not limit or contain AUKUS to non-nuclear options. This is particularly true when the US has historically provided non-nuclear long-range precision-strike capability. In the past this included the F-111 Aardvark, F/A-18F Super Hornet, E/A-18G Growler, and F-35A Lightning II.

Under the UN Charter, members have “the inherent right of individual or collective self-defence if an armed attack occurs.” Hence, Australia and its allies should stand by the expression, si vis pacem, para bellum. Australia and its AUKUS allies should not back down from non-nuclear long-range precision strike capability or nuclear-armed deterrence options that provide more flexible responses.

Although, the sale of Virginia-class submarines to Australia under the AUKUS agreement may be contingent on the US Navy’s ability to maintain its submarine production rate. It is worth noting that American undersea capabilities, particularly in the long term, may be greatly enhanced through other means under AUKUS Pillar I and Pillar II.

In the new era of nuclear disorder, the key to maintaining American undersea capabilities will likely be the SLCM-N deployed on Virginia-class attack submarines. The SLCM-N will provide AUKUS flexible deterrence options and limit risk of conflict in austere Euro-Atlantic and Indo-Pacific theatres.

Natalie A. Treloar is a Senior Analyst at the National Institute for Deterrence Studies. She is the Australian Company Director of Alpha–India Consultancy. Natalie formerly contracted to the Australian Department of Defence. Views expressed in this article are solely those of the author and do not necessarily reflect the views, policies, or positions of any organization, employer, or affiliated group.

SLCM-N, the Virginia-Class Submarine, and AUKUS was originally published on Global Security Review.

Arms control and disarmament advocates differ with this view, seeing the deterrent as a risk that must be reduced in size and function via various forms of diplomacy that range from one-party declarations and codes of conduct to formal arms control agreements. These sorts of undertakings are currently moribund within officialdom, though enjoying an eternal spring of hope among the single-issue think tanks, academics, and commentators who strive to sway government.

Paradoxically the current surge in hostilities between the United States and the axis of autocracy (China, North Korea, and Russia) could furnish the spark that revives official efforts at both improving deterrence and renewed arms control. For instance, an updated Budapest Memorandum might form one component of a settlement or freezing of the Russian invasion of Ukraine. An Iranian “regime change” may also offer a path for a true and verifiable non-nuclear-weapon Iran.

The modality of any future arms control arrangement could vary greatly. Not all arms control arrangements are treaties. Given the current international situation among nuclear-armed states, treaties might indeed be the least likely of modalities. Some modalities that future arms control arrangements could take include unilateral American declarations, American-backed codes of conduct, American-backed norms, agreement within NATO (such as the Committee on Proliferation or the Nuclear Planning Group), unilateral American renewal of earlier Negative Security Assurances (such as those deposited with the United Nations), bilateral or multilateral statements, bilateral or multilateral memorandum or other agreed instrument short of a treaty, and/or bilateral or multilateral treaties.

The Process of Arms Control

All these arms control approaches present challenges to American and NATO forces. They also present opportunities to refine force posture and employment options. Three concrete steps are useful in ensuring American and alliance leadership receives constant feedback with operational decision-makers.

First, it is important to sustain collaboration. As government and American allies contemplate arms control arrangements, nuclear-force commanders should offer information on the challenges and opportunities that various permutations of an arrangement present to force posture and operations. Not all ideas are operationally possible.

Second, highlight the challenges that an arrangement poses to fielded forces. As part of any discussions, commanders should relate how they would adjust operations as nascent arrangements move toward implementation. This would likely be a stepwise evolution of operations in reaction to implementation of disclosures and intrusion that could accompany various forms of arms control measures. Policymakers rarely understand what their aspirational objectives mean for operational forces.

Third, highlight opportunities an arrangement creates for forces. Similarly, commanders should monitor the evolution of arms control arrangements and be on the lookout for arrangements that permit gleaning information about adversary forces—information that is useful in crafting the best force posture, plans, and operational tactics.

These feedback loops would evolve in phases over the time that an arms control arrangement is contemplated, refined, and implemented (or rejected).

The Phases of Arms Control

Any future arms control agreement should have six phases:

Phase 1 takes place during internal American contemplation of potential arms control arrangements. Classified analysis of changes to operations that an arrangement might necessitate are discussed. When inspections are proposed, any detrimental effects to operations from various forms of inspection are discussed. Discussing the benefits of inspecting adversary installations is also an important consideration. 

Phase 2 occurs during outreach with adversaries and third-country parties. Internal “food-for-thought” papers from the operational community are prepared for negotiators and strategic-communications personnel. Deliberate public statements such as editorials and conference presentations serve a useful purpose in explaining American interests.  

Phase 3 takes place during formalization of an arms control arrangement. When requested by the Department of Defense, Department of State, National Security Council, the president, or other officials, public statements are made for adversary consumption. 

Phase 4 is the implementation phase. This is the period in which an arms control arrangement comes into effect by treaty agreement or as a unilateral/bilateral/multilateral action. Classified reports on implementation progress of the new arrangement are prepared. When inspections are part of the arrangement, coordination between government agencies occurs.

Phase 5 is focused on sustainment. During this period an arms control arrangement is in effect. Classified reports address difficulties from the arrangement. 

Phase 6 is the sunset period. This is when the arms control arrangement ends or appears to be faltering. Analysis of the operational steps, timeline, costs, equipment, and personnel necessary to terminate the arms control arrangement is conducted. Classified reports on progress toward ceasing any earlier changes to operations and capabilities, necessitated by the arrangement, are conducted.

Conclusion

Arms control for the sake of arms control was always a bad idea. The United States is no longer in a position where it can enter into arms control agreements because it furthers an idealist ambition to promote peace. Today, arms control is only useful if it furthers American interests.

Taking a hard-nosed look at arms control in its various forms is necessary, but it must be acceptable for the answer to be no. The United States is no longer in a position to act altruistically. Russia is a superior nuclear power, and China may reach a similar status within a decade. The world has changed and American leaders must accept that its adversaries are no longer willing to follow America’s lead.

Professor Stephen Cimbala, PhD, is a professor at Penn State-Brandywine. Views expressed are his own.

An Uncertain Future for Arms Control was originally published on Global Security Review.