Doomsday Clock at 85 Seconds: New START Treaty Expiration Heightens Global Catastrophe Risks

The Doomsday Clock has been set to 85 seconds to midnight, marking its closest position to a symbolic global catastrophe since its inception in 1947. This adjustment, announced in 2025, reflects a lack of progress in addressing nuclear risks, the climate crisis, biological threats, and disruptive technologies. A significant contributing factor to the heightened concerns is the expiration of the New Strategic Arms Reduction Treaty (New START) in early February 2026, which leaves the United States and Russia without binding limits on their nuclear arsenals for the first time in over 30 years, raising international concerns about an unconstrained arms race.

Doomsday Clock Set to Record Close

The Bulletin of the Atomic Scientists announced in 2025 that its Doomsday Clock, a symbolic representation of humanity's proximity to self-destruction, was set to 85 seconds to midnight. This adjustment marks the closest the clock has been to midnight since its establishment in 1947. Midnight on the clock signifies a point where Earth could become uninhabitable due to human actions.

The Doomsday Clock was created in 1947 by the Chicago-based non-profit Bulletin of the Atomic Scientists, founded by scientists involved in the Manhattan Project. Initially set at seven minutes to midnight, its purpose was to measure nuclear threats. In 2007, its calculations expanded to include the climate crisis. The time is set annually by experts from the Bulletin's science and security board, in consultation with its board of sponsors, which was formed in 1948 by Albert Einstein and included J. Robert Oppenheimer as its first chair. The board currently includes eight Nobel laureates.

The clock is intended to foster discussions about global crises rather than to definitively measure existential threats.

Its setting has been reset 27 times, reaching its furthest point from midnight at 17 minutes in 1991, following the Strategic Arms Reduction Treaty (START) and the collapse of the Soviet Union.

Factors Contributing to Doomsday Clock Adjustment

The 2025 adjustment reflects insufficient global progress in addressing several critical challenges. Alexandra Bell, President and CEO of the Bulletin, noted that "catastrophic risks are on the rise, cooperation is on the decline." Key factors identified include:

• Increasing nuclear risks.
• The climate crisis.
• Biological threats.
• Advances in "disruptive technologies" such as artificial intelligence.
• The proliferation of misinformation, disinformation, and conspiracy theories.

Dr. Daniel Holz, chair of the Bulletin's science and security board, noted that major countries have become "increasingly aggressive, adversarial, and nationalistic," intensifying conflicts. He highlighted persistent dangers in the life sciences, particularly in areas like synthetic mirror life development, and the absence of a coordinated international plan for biological threats. The rapid growth and unregulated use of AI tools were also cited as factors that could exacerbate other issues.

A significant concern highlighted by the Bulletin and its experts is the expiration of the New START treaty, described as the last remaining nuclear weapons treaty between the United States and Russia.

New START Treaty Officially Expires

The New Strategic Arms Reduction Treaty (New START), which established limits on strategic offensive arms between the United States and Russia, officially expired in early February 2026. This development signifies the absence of legally binding limits on the nuclear arsenals of the two nations for the first time since 1991.

Background of the Treaty

Negotiated in 2010 by then-Presidents Barack Obama and Dmitry Medvedev, the New START treaty was a continuation of arms control efforts dating back to the Cold War. It initially set limits on each side to:

• No more than 1,550 deployed nuclear warheads.
• No more than 700 deployed intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy bombers equipped for nuclear weapons.
• No more than 800 deployed and non-deployed launchers.

The treaty included a comprehensive framework for notification, inspection, verification, and compliance, with over 25,000 data exchanges over its lifespan. On-site inspections, a key verification mechanism, were suspended in 2020 due to the COVID-19 pandemic and did not resume.

Initially a 10-year agreement, the treaty came into effect in 2011 and was extended for an additional five years in 2021, through February 2026. It was not eligible for further extensions, though both countries could have agreed to continue adhering to its caps. Russia and the United States together possess approximately 90% of the world's nuclear weapons.

Developments Leading to Expiration

In February 2023, Russian President Vladimir Putin announced Russia's suspension of its participation in the treaty, citing US support for Ukraine and "other hostile actions of the west." While Russia clarified it was not withdrawing entirely and pledged to respect the numerical caps, it did not maintain the inspection processes. The United States responded by suspending its obligations to allow Russian inspections.

Former US President Donald Trump had previously expressed a lack of interest in extending the treaty, advocating for a "better agreement" that would include China. Russian President Vladimir Putin had proposed observing weapon caps for an additional year if the US responded similarly, an offer that the US did not accept. Kremlin spokesperson Dmitry Peskov stated Moscow viewed the expiration "negatively" but would act in a "balanced and responsible manner."

Perspectives on Expiration and Future Outlook

The expiration has raised international concerns about a potential unconstrained nuclear arms race. UN Secretary-General António Guterres called it a "grave moment for international peace and security" and noted that the risk of nuclear weapon use is at its highest in decades. Arms control advocates, including Daryl Kimball of the Arms Control Association, warned of a "dangerous three-way arms race" if the US and Russia increase their arsenals, potentially prompting China to accelerate its own build-up.

Experts such as Gareth Evans, former Australian foreign minister, described the treaty's end as a "terrifying prospect," while Tilman Ruff, co-founder of the International Campaign to Abolish Nuclear Weapons (ICAN), stated it "will bring a definitive and alarming end to nuclear restraint."

The Nuclear Threat Initiative (NTI) warned of "potentially unconstrained nuclear build-ups," potentially more complex than the Cold War era due to China's nuclear expansion and emerging technologies.

Some experts, however, argued that the treaty's limitations were outdated and constrained the US, particularly as China expands its nuclear arsenal. Matthew Kroenig of the Atlantic Council suggested that the primary goal of US nuclear weapons is to deter war, and existing limits may be insufficient to deter both Russia and a rapidly growing China.

China's Stance

China has consistently rejected participation in trilateral arms control negotiations, stating that its nuclear forces are not comparable in scale to those of the US and Russia. A 2022 Pentagon report projected that China could possess 1,500 nuclear warheads by 2035 at its current expansion rate. Beijing expressed regret over the New START expiration and called on the US to resume nuclear dialogue with Russia and to observe the treaty's core limits for the time being.

Context of Global Strategic Competition

The expiration of New START coincides with broader shifts in the global geo-strategic order. Rose Gottemoeller, former chief US negotiator for New START, warned of a scenario where Russia could rapidly upload additional nuclear warheads, potentially outpacing the US. The US is currently undertaking a trillion-dollar upgrade to its existing nuclear arsenal over the next decade.

Preceding arms control efforts between the US and Russia include the SALT I agreements and the 1972 Anti-Ballistic Missile (ABM) Treaty, from which the US withdrew in 2001. The 1987 Intermediate-range Nuclear Forces (INF) Treaty was terminated in 2019. In response to US missile defense efforts and treaty terminations, Russia has ordered the development of new weapons systems, including the Burevestnik nuclear-tipped cruise missile and the Poseidon nuclear-armed underwater drone, both of which reportedly underwent successful tests in 2023.

In Europe, the UK and France, both nuclear powers, have engaged in discussions regarding the alignment of their nuclear programs within NATO. Other European nations, including Sweden, Poland, and Germany, are reportedly debating the development of their own nuclear weapons capabilities, with German Chancellor Friedrich Merz exploring concepts for a shared nuclear umbrella.

Calls for Action

UN Secretary-General Guterres urged both the US and Russia to resume negotiations for a verifiable successor framework. Tilman Ruff of ICAN emphasized the increasing urgency for more countries to commit to the UN Treaty on the Prohibition of Nuclear Weapons, the only internationally agreed framework for the eventual elimination of nuclear weapons.

The Bulletin of the Atomic Scientists believes that because humans created these threats, they can also reduce them, requiring global engagement and serious work. They suggest individual actions, such as discussing these issues, can help combat misinformation and encourage leaders to act.