Some eighty years after the bombings of Hiroshima and Nagasaki, the global community still struggles with the strategic, political, and ethical implications of nuclear arms races. The Cold War’s bipolar competition once defined the global nuclear dynamics, but today’s landscape is more complex, involving multiple nuclear-armed states, emerging technologies, and shifting geopolitical alliances.  

From Bipolar to Multipolar Competition and Arms Racing  

During the Cold War, the United States and the Soviet Union engaged in a massive arms buildup driven by deterrence theory, ideological rivalry, and fears of vulnerability. The end of the Cold War lowered tensions and decreased the number of nuclear weapons, but it did not eliminate them completely. Instead, the global system has evolved into a multipolar environment with nine nuclear-armed states, each with distinct strategic cultures and security concerns. Although most states in the United Nations have endorsed the principle of nuclear disarmament, no current nuclear weapons state has embraced the concept or taken even small steps in that direction.  

New Drivers of Competition  

The current nuclear environment is shaped by a mix of technological advances, growing regional rivalries, diminishing arms control agreements, and renewed great-power competition. Unlike the organized bipolar order of the Cold War, today’s strategic landscape is becoming more multipolar, faster-paced, and less predictable based on emerging factors. 

 Technological innovation: Hypersonic weapons, cyber capabilities, artificial intelligence, and missile defense systems introduce new uncertainties about the survivability of nuclear arsenals. Another source of potential instability is the growing effectiveness of conventional weapons for long‑range precision strike, with destructive capabilities that might provoke a responsive nuclear first use or first strike. In addition, modern information and manufacturing systems, compared to earlier generations, shorten the timelines between concept and prototype, and between prototype and mass production.  

Regional rivalries: Regional military competition between India and Pakistan, North Korea and South Korea, China and India, and among China, North Korea, Japan, and the United States, threatens to escalate conventional war into nuclear first use, and even short of crossing the nuclear threshold, exacerbate regional and global nuclear tensions.  

Erosion of arms control: The termination of nuclear arms control agreements, such as the Intermediate-Range Nuclear Forces (INF) Treaty and the New START Treaty, has created a situation of arms control anomie that invites competitive distrust among nuclear powers and increases uncertainty about their nuclear‑strategic thinking.  

Great‑power competition: The almost inevitable arrival of China as a third nuclear superpower creates an additional axis of uncertainty compared to the two‑sided Cold War rivalry between the Soviet Union and the United States. China’s involvement in a tripartite format for exchanging strategic thinking on nuclear weapons and arms control is an important, albeit challenging, imperative for all three states and their military leaders.  

Risks and Consequences of Renewed Arms Races  

The modern nuclear landscape is increasingly defined not only by military competition but also by growing concerns over strategic stability, economic sustainability, and ethical responsibility.  

Strategic Instability: As states pursue more sophisticated and diversified arsenals, the risk of miscalculation grows. Technologies that compress decision‑making time—such as hypersonic glide vehicles or AI‑enabled early‑warning systems—could increase the likelihood of accidental or preemptive nuclear use. AI‑enhanced technology for intelligence, warning, and estimation of others’ options and intentions will become standardized among great powers, raising the issue of shared guardrails in military applications of AI technology for crisis management.  

Economic and Opportunity Costs: Nuclear modernization programs require enormous financial investments. For many states, the pursuit of nuclear capabilities reflects a tradeoff between perceived security benefits and long‑term societal needs. Even within the umbrella of defense needs per se, there are important tradeoffs among preferred weapons systems and supporting infrastructure. For example, in the case of the United States, the costs of developing and deploying the proposed Golden Dome antimissile defense system may compete with the demands of military services for new generations of offensive strategic nuclear weapons.  

Normative and Ethical Concerns: The continued reliance on nuclear weapons raises profound ethical questions. The humanitarian consequences of any nuclear exchange—intentional or accidental—would be catastrophic. The potential erosion of norms against nuclear testing and against cavalier threats of nuclear first use threatens decades of progress toward the avoidance and management of nuclear crises.  

Future Pathways: Escalation or Restraint?  

As nuclear and non-nuclear systems become increasingly entangled, states, international institutions, and civil society organizations will play an important role in developing risk-reduction measures, strengthening strategic dialogue, and preserving norms to prevent nuclear escalation and maintain global stability.  

Technological Governance: Technological “black swans” have the potential to upend previously understood mechanisms for reassuring nuclear-weapon states against fears of preemptive nuclear attack. As AI, cyber operations, and autonomous systems become intertwined with nuclear command and control, states may need new norms or agreements to prevent destabilizing uses. Establishing shared understandings of “red lines” in cyber‑nuclear interactions could be a starting point.  

Regional Security Architectures: In regions with acute nuclear tensions, tailored diplomatic frameworks may help reduce risks. Confidence‑building measures in South Asia, renewed dialogue on the Korean Peninsula, and discussions on European security could all contribute to stability. The containment of growth in the numbers and lethality of non‑strategic or tactical nuclear weapons, in the context of preserving regional deterrence and security, is of immediate importance.  

The Role of Civil Society and International Institutions: Nongovernmental organizations, academic institutions, and international bodies continue to play a vital role in shaping public discourse, conducting research, and advocating for risk-reduction measures. Their influence may be especially crucial as formal diplomatic channels encounter political obstacles. One challenge is the relative shortage of nuclear deterrence and arms control studies in research university departments nowadays, compared to the Cold War and immediate post-Cold War periods.  

Conclusion  

In the twenty-first century, nuclear arms racing is no longer defined by the relatively stable bipolar logic of the Cold War, but by a far more complex and uncertain multipolar environment shaped by emerging technologies, regional rivalries, weakened arms control structures, and renewed great-power competition. The combination of emerging technology and increasingly sophisticated strike systems has compressed decision-making timelines and introduced new risks of miscalculation, escalation, and strategic instability among nuclear-armed states. At the same time, the financial costs of nuclear arsenals and the potential catastrophic humanitarian consequences of any nuclear exchange continue to raise profound ethical and political questions about unchecked nuclear capacities.  

Preventing future nuclear crises will require renewed commitments to arms control, technological governance, regional confidence-building measures, and sustained dialogue among both states and nonstate actors. In an era when formal diplomatic channels are increasingly strained, international institutions, academic communities, and civil society organizations may help preserve norms of restraint and advance practical risk-reduction measures. Ultimately, the challenge facing the international community is not only how to manage nuclear competition, but how to prevent technological change, geopolitical rivalry, and strategic mistrust from producing a new era of nuclear instability with potentially irreversible consequences.  

Stephen J. Cimbala is Distinguished Professor of Political Science at Penn State Brandywine and the author of numerous works on nuclear deterrence, arms control, and military strategy. He is a senior fellow at NIDS and a recent contributor to the Routledge Handbook of Soviet and Russian Military Studies edited by Dr. Alexander Hill (Routledge: 2025). The views of the author are his own. 

Arms Control is No Panacea, But It Helps was originally published on Global Security Review.

With the New START’s expiration on February 5, 2026, the world has entered a new era in nuclear arms control, reflecting the evolving realities of the contemporary nuclear order. The United States believes that nuclear limits on warheads and launchers imposed under the New START no longer serve its interests, or those of its nuclear adversaries, highlighting Washington’s lack of appetite for a renewed bilateral arrangement. Dr. Christopher Yeaw, the U.S. Assistant Secretary of State for the Bureau of Arms Control and Non-Proliferation, shared the U.S. perspective at the Conference on Disarmament (CD), shifting from exclusive U.S.-Russia strategic constraints toward a more inclusive yet complex multilateral framework that could shape the future of global nuclear stability. This transition shows a broader shift in arms control policy of the U.S., emphasizing the need for a new arms control arrangement that reflects a transition from a bilateral framework to a multilateral charter, holding all five nuclear-weapon states under the Treaty on the Non-Proliferation of Nuclear Weapons (P-5) equally responsible for making serious efforts toward nuclear disarmament.

While addressing the CD, Dr. Yeaw used the shortcomings of the New START to advance a broader strategic argument rather than merely listing Russian violations. By emphasizing Russia’s sizeable stockpile of non-strategic (theatre) nuclear weapons that are estimated to be around 2,000 warheads and the production of novel systems like nuclear-armed Skyfall cruise missile and the nuclear powered Poseidon torpedo, Washington aimed to highlight that New START was overly focused on deployed strategic warheads and completely overlooked the full range of modern nuclear risks.

Dr. Yeaw further linked these loopholes with China’s emergence as a major nuclear actor, arguing that the New START bilateral structure left a structural gap by excluding Beijing at a time of unprecedented expansion in its nuclear arsenal. While projecting on China’s official defense white papers, he cautioned that Beijing could attain strategic parity in the next four to five years and may possess fissile material sufficient for more than 1,000 warheads by 2030, which was roughly 200 at the time the treaty was signed in 2010. Additionally, he highlighted concerns about Russian cooperation on China’s CFR-600 reactors, framing this collaboration as further complicating U.S. threat perceptions. Through these arguments, Washington justifies a shift from a bilateral arms control framework with Russia toward a multilateral platform that includes additional nuclear stakeholders, reflecting a recalibration of the U.S. arms control policy in the contemporary multipolar nuclear landscape.

The U.S. believes that New START’s expiration arrived at the fortuitous time, urging all states, not just the nuclear-weapon states, to strive for a better arms control framework. Under the new proposal, Washington aims to transition from a bilateral arms control agreement with Russia to a multilateral platform as a necessary next step in ongoing arms control discussions. Such a multilateral format can prevent an unmitigated nuclear arms race, restrain the build-up of nuclear arms, and address issues surrounding non-NPT states with nuclear weapons. In a multilateral format, the Trump administration says all options are on the table as it discusses the future of nuclear arms control in the current security environment. Washington wants to conduct negotiations on strategic stability and arms control on multiple avenues, including the P5 forum where NPT-recognized nuclear-weapon states already meet to discuss issues of strategic importance. The Trump administration maintains that all five nuclear-weapon states (P5) are under an obligation to negotiate nuclear disarmament in good faith under Article 6 of the Nuclear Non-Proliferation Treaty (NPT), and that disarmament efforts are not limited to those states with the largest arsenals. Under this new proposal, the U.S. wants nuclear weapon states like Russia and China to participate in a multilateral process for effective debate on the elements of arms control arrangements.

In the evolving multipolar nuclear order, bringing together all five nuclear-weapon states to the NPT – Russia, China, France, the United Kingdom, and the U.S. admits that today’s strategic stability extends beyond Russia-U.S. dynamics. This forum could prove effective in preserving normative commitments under the Nuclear Non-Proliferation Treaty. However, asymmetries in nuclear capabilities and divergent threat perceptions limit the viability of such a multilateral forum. The U.S. and Russia still possess 80 percent of the global nuclear arsenal, while Beijing would resist numerical limits without prior reductions by the U.S. and Russia. France may support such a multilateral dialogue with other P5 states, maintaining its independent nuclear deterrent. However, Paris would likely resist any binding multilateral commitments that could limit its small arsenal. The United Kingdom may support the U.S. initiative for expanding P5 engagement.

The imperative of arms control is encouraging, but given the evolving global nuclear order, where New START failed to achieve its objectives, it is difficult to see how the proposed multilateral, modernized approach might succeed soon. In this scenario, a multilateral forum like the P5 would remain a consultative platform rather than serve as a substitute for enforcing arms control agreements.

In conclusion, after New START’s expiration, the U.S. has moved from bilateral arms control with Russia to a broader multilateral strategy, encouraging all NPT nuclear-weapon states, through forums like the P5, to share responsibility for strategic stability. This favors a more flexible approach to multilateral engagements over the binding bilateral constraints of the past in a changing security environment.

Nawal Nawaz is a researcher at the Centre for International Strategic Studies (CISS) in Islamabad. She is pursuing her MPhil in Strategic Studies at the National Defence University in Islamabad, focusing on nuclear deterrence, arms control, and regional strategic stability.

From Bilateralism to Multilateralism: Washington’s Push for Strategic Stability Through the P5 was originally published on Global Security Review.

The return of great power competition is especially concerning in the Indo-Pacific, with the expansion of Chinese military capabilities eroding the status quo of a regional rules-based order. An evolution in Chinese strategic objectives has created a shift among American defense planners and strategists, who now see China as the primary adversary of the United States. As written within the 2022 U.S. National Defense Strategy, “The [People’s Republic of China] PRC remains our most consequential strategic competitor for the coming decades… this conclusion [is based] on the PRC’s increasingly coercive actions to reshape the Indo-Pacific region and the international system to fit its authoritarian preferences, alongside a keen awareness of the PRC’s clearly stated intentions and the rapid modernization and expansion of its military.”

In the Cold War, Western strategists and planners spent most of their intellectual capital examining the challenges posed by the Soviet Union, in particular, the deterrence challenges posed by the Soviet nuclear arsenal. Policymakers subsequently developed defensive strategies and associated concepts including extended deterrence and force posturing in Europe and the role that the American industrial, economic, and military could play. Not least among these considerations was the role of U.S. extended deterrence commitments to its allies in NATO, particularly those allies on the front lines of the Cold War stand-off in Europe.

Put simply, extended deterrence refers to the stated policy to defend a foreign ally, including the use of nuclear weapons in said defense, as part of a mutual defense treaty. Many policies supported the credibility of U.S. extended deterrence commitments in Europe, to include public statements by American presidents, the presence of American military personnel abroad, and U.S. nuclear weapons forward deployed in Europe. Extended nuclear deterrence, along with the forward deployment of vast amounts of conventional power, was a central element of America’s defense of its European allies. One of the factors that strengthened the conventional defensive posture of Europe is that Europe enjoys a certain amount of strategic depth.

Strategic depth is defined as the space available within a territory to halt an adversary attack, execute a counterattack, and end the conflict on terms acceptable to the counterattacking party. During the Cold War, NATO enjoyed a regional depth which allowed not only for NATO forces to fall back to more defendable geographic features in the face of a conventional attack, such as the Rhine, the Rhone, or even the Pyrenees, but strategic depth within Europe allowed either side to carry out strikes on European soil without escalating or expanding the conflict to a nuclear war on each other’s homelands.

While this geography served U.S. and allied interests in the Cold War, the United States lacks a similar level of strategic depth in the Indo-Pacific as it confronts the prospects of a large-scale conflict with China. Much of the geography in a U.S.-China conflict would take place over the open ocean and skies of the Western Pacific. As such, there are few defendable terrain features such as rivers or mountain ranges behind which an actor can rest, reset, and prepare for a counterattack.

Just as importantly, a battlefield in the Western Pacific means that there are fewer options for the distribution of basing. American and allied bases would therefore have to generate combat operations from a limited number of high priority bases in a conflict. The lack of defensible features and small number of high-value bases is in many ways the opposite condition of what the United States and its NATO allies experienced in the Cold War.

In contrast, China has enormous strategic depth due to its ability to generate combat power from any number of bases, launch sites, or ports along its enormous Pacific coast and its deep hinterland. In the Western Pacific, U.S. allies and partners are dispersed and in some cases thousands of miles away from each other, with neutral and non-aligned states dotted in between. As a result of the United States’ limited number of bases, owing to the scarcity of permanent land features in the Western Pacific, China can focus on a small number of critical targets to diminish American and allied combat effectiveness.

Further, the limited number of in theater bases increases the demands and stress on an aerial fleet and the logistics involved in keeping U.S. forces adequately supplied. It also makes for significantly longer ship and submarine transit times to and from more distant resupply points. Already in 2015 there was the issue of the rate at which missiles can be launched.

To counter China, the number and availability of sensor resources that can be devoted to integrated air and missile defense systems versus other missions must increase given the vertical proliferation of such systems. Also, the capacity of combat logistics forces needed to cycle ammunition ships between rear bases and forward reloading areas, maintain long-range, high-capacity carrier-based aerial refueling, and to sustain different operational concepts over prolonged periods of conflict must be expanded.

The United States, Japan, and Australia should consider pre-positioning substantial amounts of military capabilities directly relevant to deterrence operations, such as missile defense capabilities, fuel, and conventional munitions, in each other’s territories to create targeting dilemmas for China. Doing so would not only enhance knowledge of deterrence methods and challenges between allies in theater that are vastly different from Western Europe during the Cold War but also create existential misery for PRC defense planners.

Regardless of personal preference, complex issues related to nuclear strategy are now central in the Indo-Pacific region. The U.S. and its allies must deliberately evaluate the profound responsibilities that come with being members of a nuclear alliance.

Robert Peters is a Senior Research Fellow for Strategic Deterrence in The Heritage Foundation’s Allison Center for National Security. Prior to joining Heritage, Peters served as the lead strategist at the Defense Threat Reduction Agency, where he oversaw the office that developed the Agency’s five-year strategy, conducted the Agency’s research and tabletop exercise program, and executed Agency-level program evaluations. Dr. Christine Leah is a Fellow at the US National Institute for Deterrence Studies and has worked on nuclear issues at Yale, MIT, and RAND and in London, Singapore, and Canberra. She is the author of The Consequences of American Nuclear Disarmament and Australia and the Bomb. Views expressed by the author’s are their own.

Extended Deterrence and Strategic Depth was originally published on Global Security Review.

ICBM EAR Report for 22 Feb 2025 was originally published on Global Security Review.

Overview

The report, prepared by Peter Huessy, comprehensively assesses nuclear deterrence, strategic security issues, and emerging threats. It includes key quotes from U.S. leaders, updates on nuclear modernization, policy discussions, and geopolitical analysis.

Key Themes & Highlights

1. Strategic Nuclear Posture & Modernization:
   • U.S. nuclear deterrence strategies are facing significant challenges, with adversaries such as Russia and China expanding their arsenals.
   • The U.S. Air Force has paused elements of the Sentinel ICBM program due to evolving requirements.
   • Modernization efforts include upgrades to the B61 and B83 nuclear gravity bombs, though concerns persist regarding the adequacy of U.S. capabilities against hardened enemy targets.
2. Policy & Leadership Insights:
   • Secretary of Defense Peter Hegseth emphasizes the need to rebuild the military’s warrior ethos and align capabilities with threats.
   • House Armed Services Committee (HASC) Chairman Mike Rogers stresses the necessity of increased defense spending to counter global threats.
   • Former President Donald Trump calls for nuclear arms control talks with Russia and China, while also questioning the need for new nuclear weapons given existing stockpiles.
3. Geopolitical Developments & Deterrence Challenges:
   • Concerns over a growing Sino-Russian-North Korean-Iranian alignment seeking to undermine the Western security order.
   • Debate over extended nuclear deterrence and the potential for allied nations to develop independent nuclear capabilities.
   • The future of U.S. nuclear triad strategy amid reports of China’s advancements in submarine detection technology.
4. Ukraine Conflict & U.S. Policy:
   • Differing views on U.S. involvement in Ukraine, with some advocating for continued support while others argue for de-escalation and negotiations.
   • Analysis of Russian vulnerabilities, including internal instability and the potential for civil unrest post-Putin.
5. Congressional & Budgetary Updates:
   • The House Budget Committee supports increased defense spending, with an additional $100 billion allocated for the next year.
   • Senate Majority Leader John Thune discusses priorities related to Air Force modernization, including the B-21 bomber program.
6. Emerging Threats & Strategic Risks:
   • Reports suggest that China has developed new submarine detection technologies that could undermine the stealth advantage of U.S. nuclear submarines.
   • Analysis of the potential consequences of Vladimir Putin’s downfall, including the risk of nuclear proliferation due to internal instability in Russia.

Download the full report

ICBM EAR Week of February 10, 2025 was originally published on Global Security Review.

Today, modernization efforts are underway among all nuclear weapons states (NWS), who must acknowledge how their nuclear-based actions and rhetoric impacts global security through incentivizing proliferation for non-nuclear weapons states (NNWS). Moreover, the world must not forget the effects of actual nuclear use or the potential for catastrophic escalation to follow. Hiroshima and Nagasaki may represent victory achieved by nuclear use to some, but there is no direct analogy to the present day.

On the Horizon?

The potential for nuclear war began in August 1949, when the Soviet Union tested its first atomic bomb. After the Cuban Missile Crisis (1962), bilateral and multilateral treaties focused on nuclear arms control. Such efforts served a vital role then, as they do today, for strategic stability and mutual security.

The cornerstones of nuclear arms control include 2011’s New START, plus the original nuclear agreement, and the 1968 Treaty on the Non-Proliferation of Nuclear Weapons (NPT). Russia suspended participation in New START in August 2022, ultimately exacerbating tensions amidst the war in Ukraine. Russian president Vladimir Putin’s nuclear threats are also increasing nuclear tensions. While the NPT remains active with 191 signatory states, its intention to prevent the further spread of nuclear proliferation is threatened by increasingly aggressive nuclear rhetoric surrounding nuclear strikes and first use. Such concerns stem from Russia’s invasion of Ukraine, as well as its, China’s, and North Korea’s vertical proliferation.

Japan is one of many states with the ability to develop nuclear weapons and is experiencing increasing incentives to do so. The cost-benefit analysis of nuclear proliferation is a frequent focus amongst theorists, with the commonality being credible existential threat(s) to a state. Japan experiences this regionally from China and North Korea and more broadly from Russia. Though the United States provides a nuclear umbrella to its Pacific allies, which it continuously reaffirms, discussion in South Korea and Japan suggests growing support for independent nuclear arsenals. This adds to the concern that Japan, for example, might develop its own nuclear weapons.

The Japanese Perspective

Even with existential threats posed by nuclear-armed adversaries, most Japanese citizens are opposed to nuclear proliferation and nuclear use. According to public opinion polls, 75 percent of Japanese citizens support the Treaty on the Prohibition of Nuclear Weapons (TPNW). They believe so strongly in the nuclear taboo that 58 percent denounce nuclear use, even in retaliation to a nuclear attack.

This sentiment is strong in no small part because of their very direct experience through Hiroshima and Nagasaki. Survivors of the Hiroshima bombing—alongside Nagasaki—advocate for peace. They see warfare and the employment of nuclear weapons as unavoidably devastating to civil society. Survivor Toshiko Tanaka advocates for peace through nuclear disarmament, arguing that the world must remain consciously aware of nuclear war’s aftermath. The city of Hiroshima also holds annual commemorations on the bombing’s anniversary—along with housing museums and memorials intended to be a stark reminder of the consequences of war.

“The Only Winning Move is [Still] Not to Play”

Japanese surrender in 1945 stemmed from several factors that cannot be replicated in the age of multiple nuclear-armed states. Imperial Japan started the war in the Pacific with invasions of China and other Asian nations before eventually launching a surprise attack on the United States. By the time Japan surrendered, it took the emperor imposing his will on a military that sought to fight to the bitter end. For some of the military leadership, the physical effects of the atomic bombs were comparable to the firebombing long underway.

Today, however, nuclear weapons are far larger and more numerous, making the effects far greater for any society that may experience nuclear employment. Thus, avoiding highly destructive conventional wars with the potential for uncontrolled nuclear escalation is important.

The threat posed by nuclear weapons to non-nuclear states may be much higher than previously believed. The Russian invasion of Ukraine and Russia’s threats to use nuclear weapons against a non-nuclear Ukraine are worrisome. Expanding Chinese and North Korean nuclear arsenals and Iran’s likely nuclear breakout are also worrisome. Moreover, some US political thinking combines with its ballistic missile defenses to lean into isolationist tendencies that stress extended deterrence credibility.

Any nuclear use is likely to receive strong condemnation from the international community. The consequences of international condemnation and the uncertain consequences for use may be enough to prevent the employment of nuclear weapons, but there is no guarantee. Whether limited or large scale, the use of nuclear weapons will likely end efforts to prevent nuclear proliferation, including 79 years of historical precedent prioritizing diplomacy, reduction, and verification. This would be a world that neither NWS nor NNWS should wish to see. And to its survivors, remembering the Hiroshima of 1945 serves as a stark reminder of the cost of nuclear employment.

Deterring the use of nuclear weapons must remain a priority for the United States. The optimism for disarmament that won former President Barack Obama the Nobel Prize in 2009 has mostly eroded, and nuclear-armed adversaries show little interest in resuming talks much less action. Therefore, the United States must accomplish its nonproliferation objectives through the strength found in its nuclear modernization and commitments to allied defense.

Amanda Hart is a recent graduate from Virginia Tech, currently working in the field of C-WMD planning and support. Views expressed are the author’s own.

Proliferation Motivations and Modern Japan: Lessons Since Hiroshima was originally published on Global Security Review.