The New Strategic Arms Reduction Treaty, commonly known as New START, stands as the last major pillar of nuclear arms control between the United States and Russia, the world’s two largest nuclear powers. Signed in 2010 by Presidents Barack Obama and Dmitry Medvedev, it limits each side to 1,550 deployed strategic nuclear warheads and 700 deployed missiles and bombers. Extended in 2021 to February 5, 2026, the treaty has provided a framework for verification and transparency, including on-site inspections and data exchanges. However, as of November 2025, the agreement teeters on the edge of collapse amid escalating geopolitical tensions, Russia’s suspension of participation in 2023, and stalled negotiations. This unraveling not only risks igniting a new arms race but also heightens the potential for nuclear miscalculation, undermines global non-proliferation efforts, and destabilizes international security in an era of multipolar threats.
The treaty’s origins lie in the post-Cold War push for disarmament. Building on earlier agreements like the 1991 START I and the 2002 SORT, New START aimed to reduce the risk of nuclear conflict by capping arsenals and fostering mutual trust through verifiable measures. For over a decade, it succeeded in stabilizing strategic forces, with both nations complying until the Ukraine crisis erupted. In February 2023, Russian President Vladimir Putin announced the suspension of Russia’s involvement, citing Western support for Ukraine and alleged U.S. violations, though inspections had already halted due to the pandemic and travel restrictions. The U.S. countered by ceasing data sharing, further eroding the treaty’s mechanisms. As the 2026 expiration looms, experts warn that without renewal or a successor, the world could enter an unregulated nuclear landscape for the first time in over 50 years.
Recent developments highlight the precarious state of affairs. In October 2025, Putin proposed a one-year extension of New START’s terms without preconditions, emphasizing Russia’s readiness to adhere to limits while urging Washington to reciprocate. U.S. President Donald Trump responded positively, calling it a “good idea,” but skepticism abounds. Trump’s recent boasts on Truth Social about America’s superior nuclear arsenal—claiming the U.S. has more weapons than Russia—have fueled accusations from Russian lawmakers of potential treaty breaches. Such rhetoric, combined with announcements of resumed nuclear testing, signals a hardening stance that could derail talks. Meanwhile, the Physicists Coalition for Nuclear Threat Reduction noted in late October that only 100 days remain until expiration, urging enhanced arms control measures.
The threats posed by New START’s potential demise are multifaceted and profound. First and foremost is the specter of an unconstrained arms race. Without binding limits, both the U.S. and Russia could rapidly expand their arsenals. Russia, already modernizing with systems like the Burevestnik cruise missile and Poseidon drone, has tested advanced nuclear-capable weapons in October 2025. The U.S., in turn, is upgrading its triad of land-based, sea-based, and air-launched systems, with plans to deploy new missiles in Europe. Analysts project that unchecked growth could see combined stockpiles swell beyond 12,000 warheads, reminiscent of Cold War peaks. This escalation would strain budgets—Russia’s defense spending already tops 6% of GDP—and divert resources from pressing global issues like climate change and pandemics.
More alarmingly, the loss of verification regimes increases the risk of miscalculation. New START’s inspections and notifications have built confidence by allowing each side to monitor compliance, reducing paranoia about surprise attacks. Without them, ambiguities in force postures could lead to hair-trigger responses, especially amid ongoing conflicts like Ukraine. For instance, Russia’s deployment of tactical nuclear weapons in Belarus and threats over NATO involvement heighten tensions. In a multipolar world, this instability could spill over, encouraging proliferation. China, not bound by New START, is expanding its arsenal to over 600 warheads by 2025, prompting U.S. calls for trilateral talks. India, Pakistan, and North Korea are also ramping up, with North Korea’s stockpile nearing 50 warheads.
Europe feels the brunt of these risks. As the treaty falters, NATO allies worry about Russian intermediate-range missiles targeting the continent, prompting debates on enhanced deterrence. The U.S. decision to station missiles in Germany by 2026 has drawn Russian warnings of countermeasures, echoing the 1980s Euromissile crisis. Broader global security is at stake; the Stimson Center’s 2025 risk assessment ranks nuclear escalation among top threats, noting that avoiding an arms race aligns with both superpowers’ interests. Yet, domestic politics complicate renewal—U.S. hawks argue for including China’s arsenal, while Russia demands concessions on missile defense and Ukraine.
The humanitarian and environmental implications are dire. A nuclear exchange, even limited, could cause millions of deaths and trigger nuclear winter, disrupting global food systems. The Treaty on the Prohibition of Nuclear Weapons, ratified by over 70 nations but shunned by nuclear powers, gains traction as an alternative, but without U.S.-Russia buy-in, it’s symbolic. International calls for dialogue, including from the UN and EU, urge a successor treaty incorporating emerging technologies like hypersonics and AI.
As 2025 draws to a close, the window for salvage narrows. Experts like Amy Woolf advocate for U.S.-Russia-China discussions on stability principles and risk reduction, such as launch notifications. Failure to act could unravel the non-proliferation regime, emboldening rogue states and eroding deterrence. In a world grappling with conflicts in Ukraine, the Middle East, and potential flashpoints in Asia, New START’s collapse threatens to tip the balance toward catastrophe. Renewing it, or forging a new pact, isn’t just bilateral—it’s essential for humanity’s survival.
The path forward demands political will. While Putin’s proposal offers a lifeline, Trump’s administration must weigh short-term gains against long-term peace. As Russian Foreign Minister Sergey Lavrov expressed optimism for a U.S. response, the global community watches anxiously. Without arms control, the doomsday clock edges closer to midnight, reminding us that nuclear weapons respect no borders. The unraveling of New START isn’t merely a diplomatic failure—it’s a harbinger of a more dangerous world.
