What Is the Third Nuclear Age?

The world can be divided into three eras of nuclear weapons history, each defined by distinct weapons dynamics and geopolitical relationships, and distinguished by major proliferation or treaty events of its time.

The first nuclear era was characterized by a bipolar rivalry between the United States and the Soviet Union during the Cold War, from 1945 to the late 1980s. At its peak, the number of warheads held by both countries is estimated to have reached around 60,000 in 1986. This era was marked by limited arms control agreements and significant arms racing.

The second nuclear era, spanning from 1991 to 2013, saw significant disarmament through bilateral U.S.–Russia treaties such as START I and New START, which reduced global warhead numbers by a considerable amount. However, this period was also marked by nuclear proliferation efforts by regional actors, including the nuclearization of South Asia, particularly India, followed by Pakistan, and then North Korea’s decision to pursue nuclear weapons.

Beginning in 2014, the third nuclear era emerged, typified by the current, chaotic, multipolar environment. Russia has unilaterally suspended participation in New START monitoring and verification, a treaty that expired on February 5^th, 2026. Both the United Kingdom and France have commenced modernization and expansion of their nuclear forces. China is rapidly nearing an estimated 600 warheads, North Korea continues to test intercontinental ballistic missiles (ICBMs), and Russia has modernized its weapons systems and deployed short-range nuclear weapons in Belarus. Iran continues to signal that it is nearing the nuclear threshold, opacity persists regarding Israel’s nuclear capabilities, and the May 2025 conflict between India and Pakistan has created multiple additional flashpoints, all of which underscore the need for new international multilateral guardrails.

Current Global Nuclear Trends

The United States has initiated a $1.7 trillion nuclear triad modernization plan, which includes submarines, bombers, and land-based missiles. Russia has been testing nuclear-powered cruise missiles such as Burevestnik, while China is expanding its nuclear weapons capability at a rapid pace amid rising tensions over Taiwan.

In addition, strategic non-nuclear weapons, including hypersonic systems, AI-driven command structures, and missile defense, are contributing to an escalatory environment in which the nuclear ladder has become increasingly slippery to climb and equally difficult to descend. The Bulletin of the Atomic Scientists has set its “Doomsday Clock” at 89 seconds to midnight, the closest it has ever been since 1947, reflecting its assessment that the erosion of arms control, the expansion of nuclear capabilities, and the persistence of conflict have significantly increased the risk of nuclear catastrophe.

Escalating Global Nuclear Challenges

The U.S.-Russia arms control negotiations have ceased over Ukraine, and President Putin has reduced stated nuclear use thresholds. At the same time, U.S. military strikes against Iran have alarmed some observers who argue that such actions undermine norms governing sovereignty. NATO countries are increasingly exploring their own European deterrence capabilities.

A defining feature of the third nuclear age is the growing complexity of the strategic environment and the inability to manage global risks through simple bilateral frameworks.

Technological advancements that accelerate escalation risks include hypersonic weapons that challenge missile defense systems, artificial intelligence that may misinterpret launch indicators, and cyber operations that could inadvertently contribute to nuclear escalation—echoing historical false-alarm incidents in 1983. Meanwhile, China’s evolving relationship with Russia further complicates U.S. efforts to deter aggression across both Europe and the Asia-Pacific.

The Way Forward

With New START having expired, significant future limits on the number of nuclear weapons possessed by major powers appear unlikely, accelerating competition and instability. By the mid-2030s, the convergence of nuclear and advanced conventional capabilities may become normalized as tools of coercion rather than deterrence, while additional states may seek nuclear weapons should nonproliferation barriers erode. The Bulletin of the Atomic Scientists has identified the emergence of the “third nuclear age” as the top global risk in 2026.

Accordingly, new mechanisms for arms control and nuclear disarmament consistent with commitments made by major nuclear-weapon states under the NPT framework are urgently required. These include enhanced verification technologies, AI-assisted monitoring, restraints on the development of destabilizing new weapons, and sustained strategic-stability dialogue aimed at separating and disentangling nuclear and conventional escalation pathways. Additional measures to promote norms of responsible nuclear behavior are also necessary, although opposition from the five permanent members of the UN Security Council remains a significant barrier to progress. Ensuring the global security of radioactive materials must remain a priority.

The third nuclear age has placed humanity in unprecedented danger. Existing disarmament mechanisms have proven ineffective as new rivalries emerge, and technological changes accelerate. History demonstrates that diplomacy can work: New START reduced nuclear arsenals to their lowest levels since the early years of the first nuclear era. Today’s leaders must again prioritize cooperation and restraint, or risk allowing miscalculation to turn expanding arsenals into catastrophe. The alternative is too terrible to ignore.

Ms. Harsa Kakar is an Assistant Research Fellow at the Balochistan Think Tank Network (BTTN), Quetta. Views expressed in this article are the author’s own. 

Understanding the Third Nuclear Age: Why 2026 Matters was originally published on Global Security Review.

The recent defense bill passed by Congress fully supports the Sentinel program. The Strategic Posture Commission report also supports the replacement of the Minuteman III ICBM, although the commission also recommends the US examine making some portion of the ICBM force mobile. The ACA rejects efforts to make ICBMs more survivable and recommends the elimination of all American ICBMs, a switch from their previous view that the US should keep the 54-year-old Minuteman III as an alternative to Sentinel.

ICBM mobility was reviewed by previous administrations in detail, but due to opposition from environmental groups and disarmament advocates, mobile ICBMs never received the political support needed. In 1977, just after President Jimmy Carter proposed the fielding of 200 mobile MX missiles, two senators, Howard Cannon (D-NV) and Frank Moss (D-UT), cleverly proposed to the Senate Armed Services Committee that Utah and Nevada would deploy one hundred mobile MX missiles but required another state accept the other half of the force. As they anticipated, there were no takers. Thus, the nation never fielded a mobile MX missile.

In 1983, a combined mobile and fixed ICBM force that included the multi-warhead Peacekeeper and the single warhead Small ICBM, were both recommended by the congressionally mandated Scowcroft Commission. The dual system approach, noted Senator Malcolm Wallop (R-WY), was made because “[y]ou cannot make an elephant a rabbit and you can’t make a rabbit an elephant!”

In 1986, the Air Force fielded 50 Peacekeeper missiles in silos, as part of President Ronald Reagan’s nuclear modernization. However, with the end of the Cold War and a 50 percent cut to warheads under START I, plans for road-mobile Small ICBM and rail-mobile Peacekeeper missiles were both terminated.

Now, four decades later, with a nuclear arsenal 90 percent smaller than during the Cold War, the ACA rejects ICBMs altogether, whether fixed or mobile. In reality, their idea makes nuclear war more likely and does not address new strategic developments.

The most likely use of nuclear weapons is no longer a massive bolt-out-of-the blue strike, which arms control advocates cite as part of their rationale for eliminating the ICBM. The recent Strategic Posture Commission report unanimously concluded, as Mark Schneider explains, the most likely use of nuclear weapons against the United States is a coercive, but limited, nuclear strike as part of a regional conflict by Russia or China.

Within Russian strategy, limited strikes are part of an escalate to win approach that does not include strikes on American ICBMs. In fact, the very point of employing lower-yield tactical nuclear weapons is to keep strategic nuclear weapons out of the fight.

Most at risk are American military targets in Europe, the Western Pacific, and the Middle East. Here the US is already at risk with no theater nuclear forces in Asia and fewer than 200 fighter-delivered gravity bombs in Europe.

Unilaterally retiring American ICBMs from the nuclear triad would do nothing to prevent the use of nuclear weapons at either the strategic or theater level. In fact, a Russian or Chinese nuclear attack might prove more likely. For example, without ICBMs, American nuclear force structure would be reduced to five bomber and submarine bases and a handful of submarines at sea. More specifically, killing ICBMs reduces the number of targets an adversary must strike from over five hundred to about dozen—with none requiring a nuclear strike. The American deterrent is now survivable and allows for a robust second strike.

Eliminating the ICBM force invites a disarming attack by Russia or China. For example, although a majority of American ballistic missile submarines are at sea at any given time and are highly survivable, submarines are highly susceptible to conventional attack in port or when entering or leaving port. An underseas technology breakthrough would allow even our submarines at sea to be targeted.

Destroying the bomber force’s two Weapons Storage Areas before weapons are onloaded could take the bomber force out of any fight. ICBMs alone force Russia and China to expend at least 1,000 warheads in hope of destroying the force, while also knowing hundreds of American ICBMs could retaliate even after a confirmed warhead strike on the US.

An American deterrent without ICBMs invites rather than prevents aggression because it reduces the uncertainty and risk of an attack. Reducing the US nuclear force to less than a dozen aim points invites cooperative nuclear-armed adversaries to hide their intentions, promise a “peaceful rise,” and at a time of their choosing aim a possible surprise disarming strike at the United States. It also eliminates a significant hedge option for the United States.

Like the nuclear freeze, which Americans rejected half a century ago, once again the disarmament community proposes a dangerous unilateral measure that would make the very nuclear war they seek to avoid more likely. The American people must once again reject a bad idea.

Peter Huessy is Senior Fellow at the National Institute for Deterrence Studies. The view’s expressed are the authors own. 

Killing ICBMs was originally published on Global Security Review.