The Collapse of Arms Control Mechanisms and the Perils of the Third Nuclear Age

Amna Saqib

For decades, arms control regimes served as the guardrail that kept nuclear competition constrained. Treaties such as the Intermediate-Range Nuclear Forces (INF) Treaty and New START established limits on arsenals, eliminated destabilizing categories of missiles, and introduced unprecedented verification regimes that provided predictability in an otherwise precarious strategic environment. These frameworks were not ideal, but they were effective, even at the peak of Cold War tensions.  

The collapse of INF and uncertainty over New START represent not just the end of Cold War guardrails, but the failure of arms control to adapt to multipolar nuclear realities.

Today, however, these structures are eroding. The INF has collapsed, New START will expire in 2026, and no replacement is under negotiation. These developments represent the collapse of Cold War guardrails; it marks the beginning of the “Third Nuclear Age,” an era characterized by multipolar rivalry, disruptive technologies, and a significantly less margin for error. Without arms control treaties, the restraints that once moderated great-power competition have disappeared, giving way to renewed arms race, deepening mistrust, and fragile crisis stability.

The trajectory of nuclear competition can be divided into three phases. The First Nuclear Age was defined by US–Soviet bipolarity, in which the deterrence rested on the stability of a two-power system.  The Second Nuclear Age was characterized by the post-Cold War detente and arms control, while the Third Nuclear age, by contrast, is marked by less restraint, unstable rivalries and disruptive technological capabilities. Multipolarity, combined with technologies such as hypersonic weapons, missile defense, cyber operations, and AI-enabled command systems have compressed decision-making timelines and increased the risks of miscalculation. In the absence of stabilizing safeguards, mistrust rises, nuclear modernization accelerates, and crises become increasingly difficult to manage.

The stabilizing role of past treaties is well established. The first treaty to eliminate a whole category of missiles was the INF Treaty of 1987, eliminating nearly 2,700 US and Soviet missiles and established a new standard in transparency through verification. Similarly, the New START Treaty, signed in 2010, imposed restrictions on the deployed strategic warheads and delivery systems, while establishing inspection and data-exchange mechanisms that built confidence amidst the strained relations between US and Russia. Collectively, such agreements contain arms racing, reduced risk of misperception, and reflected that even adversaries divided by deep ideological differences could acknowledge the necessity of mutual constraints. The gradual erosion of these arrangements is not merely a legal setback; it signifies the dismantling of mechanisms that once provided a foundational framework for maintaining strategic stability.

The timing of the collapse of traditional arms control is particularly concerning, as it coincides with the rapid proliferation of Emerging and Disruptive Technologies (EDTs) that earlier treaties never anticipated. For instance, hypersonic glide vehicle (UGV) minimizes the decision-making windows to only a few minutes, leaving the decision makers with limited time to determine whether an incoming strike is conventional or nuclear. Likewise, missile defense systems, rather than reinforcing stability, often provoke adversaries to expand or diversify their arsenals to guarantee penetration, thereby increasing competition instead of reducing it.

Emerging technologies, hypersonics, missile defense, cyber operations, and AI are compressing decision timelines and heightening risks of miscalculation.

In addition, cyber operations create vulnerabilities for the integrity of command-and-control system, raising profound concerns regrading accountability and the preservation of human oversight. In this context, the primary threat to the strategic stability lies less in the number of that missiles states possess than in the disruptive impact of these technologies, which blur conventional thresholds and compress decision timelines. In the absence of effective arms control mechanisms to regulate their development and deployment, such technologies continue to destabilize both regional security dynamics as well as the broader global nuclear order.

The world has shifted into multipolar world order, often described as unstable (dis)order. The five nuclear flashpoints including the Korean Peninsula, South Asia, the Taiwan Strait, the Middle East, and Eastern Europe; are all characterized by unresolved disputes and weak crisis-management mechanisms, making them highly vulnerable to escalation. Yet no global framework exists to mange this complexity. The demise of INF and the uncertain future of New START thus signifying more than the demise of US–Russia restraint but also the failure of arms control to adapt to a multipolar nuclear reality. However, the Chinese nuclear forces, are still not at par with the US and Russia because history shows that major powers engage in an arms control only when their capabilities were symmetric in nature.

The South Asian region illustrates how the erosion of global arms control frameworks directly contributes to regional instability. Indian exceptionalism, reinforced through nuclear cooperation and defense agreements, has accelerated its pursuit of multiple independently targetable re-entry vehicles (MIRVs), hypersonic weapons, and ballistic missile defense systems (BMDs). India is pursuing the development of a nationwide, multi-layered BMD shield that combines indigenous interceptors with advanced systems such as the Russian S-400 missile system. While presented as a defensive measure, this ambition risks undermining regional deterrence by encouraging counterforce strategies and destabilizing South Asia’s strategic balance.

Therefore, Pakistan must opt for restrained response to Indian modernization to uphold nuclear deterrence stability. The geographical position increases this risk: with short missile flight times and limited early-warning capabilities, leaders might have only minutes to decide in a crisis. Unlike the Cold War, South Asia lacks strong hotlines, comprehensive missile test-notification agreements, or regional arms control mechanisms to prevent escalation. The crisis in the region would not remain confined; its effects would spread throughout the global nuclear order, demonstrating that the Third Nuclear Age is not a theoretical construct but a living reality.

In this context, the long-standing Pakistani proposal for a Strategic Restraint Regime of Pakistan, which includes missile-test notifications, a destabilizing deployment limit, and confidence-building measures, provides a practical mechanism for stability. Yet the initiative has received little international support. Rather, India has also been selectively accommodated into international export-control regimes, including Missile Technology Control Regime (MTCR). Such preferential treatment, together with the lack of regional restraint mechanisms, exacerbates asymmetries and increases instability. In South Asia, Pakistan should not be the only state responsible for exercising restraint; India also carries an equal responsibility to avoid actions that destabilize the region.

Extensive non-proliferation norms have also been eroded by the erosion of arms control. For decades, treaties like INF and New START symbolized that restraint was possible even during rivalry. If the leading custodians of the nuclear order no longer prioritize limits while selectively privileging certain states, smaller and excluded powers have little incentive to exercise restraint.

There has been a significant degradation of nuclear signaling. Unlike in the Cold War where the communication of deterrent messages was through the formal diplomatic and military channels, the modern signaling is being communicated in informal and performative mediums including social media. This shift not only marginalizes nuclear discourse but also increases the lack of predictability and intensifies the risk of misperception during crisis. The destabilization of the norms, combined with the emergence of irresponsible signaling practices, only exacerbates the instability.

Adapting mainly global arms control to contemporary realities is therefore essential. The immediate priority must be the extension of New START, since even limited ceilings and verification measures are preferable to unconstrained modernization. Beyond this, interim measures are needed: negotiated limits on destabilizing systems such as hypersonic, restrictions on cyber interference with nuclear command systems, and the development of global norms for crisis communication. In South Asia, institutionalized hotlines, missile-test notification agreements, and renewed engagement with Pakistan’s Strategic Restraint Regime are essential to prevent crises from escalation. None of these measures will be easy, but even partial initiatives are preferable to an unregulated race where technology outpaces diplomatic mechanisms.

The lesson of the last half-century is clear and obvious: the arms control doesn’t eliminate rivalry, but it can regulate the most dangerous outcomes of this rivalry. The Third Nuclear Age differs from the earlier eras being more multipolar, technologically complicated, and prone to error, but its risks can still be reduced. Unless urgent measures are undertaken, this era will be marked not by adaptation but by instability, reckless competition, and the increased risk of nuclear weapons.

South Asia’s fragile stability illustrates how regional rivalries and global erosion of arms control directly feed into one another, raising risks of escalation.

Arms control can’ be limited today to the old idea of disarmament alone; it must expand into a broader framework of risk management. The urgent need is to preserve and extend New START, which, despite its limitations, still provides ceilings and verification measures. Beyond this, it is necessary to have a modular approach, pursuing agreements on emerging technologies, stronger crisis-management mechanisms, and renewed global norms.

Reaffirming commitments to the Comprehensive Nuclear-Test-Ban Treaty (CTBT), preventing the weaponization of outer space, and restoring credibility to nuclear arms control would help in stabilizing the situation at the global level. Of equal importance are the regional initiatives. At the regional level, more international recognition should be given to such proposals like Strategic Restraint Regime of Pakistan, which focuses on restraint, transparency, and the prevention of conflicts in South Asia.  In the Third Nuclear Age, arms control must be adaptive, inclusive, and responsive to new technology.  If it fails to adapt these realties, the world risks descending into a nuclear predicament that will be less marked by restraint than by instability.

Amna Saqib is Research Officer & Assistant Editor at the Center for International Strategic Studies (CISS) Islamabad.