The world is on the brink of a new arms race as the last nuclear pact between the US and Russia expires, leaving the two largest atomic arsenals without any caps for the first time in over half a century. This could lead to a dangerous and unconstrained nuclear arms race, with potential global instability and increased risk of nuclear conflict.
The termination of the New START Treaty, signed in 2010, would set the stage for this scenario. The treaty, which restricted each side to no more than 1,550 nuclear warheads on no more than 700 missiles and bombers, is set to expire on Thursday. Russian President Vladimir Putin has declared his readiness to stick to the treaty's limits for another year if Washington follows suit, but President Donald Trump has been noncommittal about extending it.
Trump has indicated a desire to keep limits on nuclear weapons and involve China in arms control talks. However, Beijing has balked at any restrictions on its smaller but growing nuclear arsenal. Kremlin spokesman Dmitry Peskov warned that without limits on US and Russian nuclear stockpiles, the world would become more dangerous.
Arms control advocates have long voiced concerns about the expiration of New START, warning it could lead to a new Russia-US arms race, foment global instability, and increase the risk of nuclear conflict. Pope Leo XIV called for the treaty not to be abandoned without ensuring its concrete and effective continuation.
The failure to agree on keeping the pact's limits will likely encourage a bigger deployment, according to Daryl Kimball, executive director of the Arms Control Association. Kimball warned that the two sides could increase the number of nuclear weapons deployed on each side, opening up the possibility of an unconstrained, dangerous three-way arms race involving China.
Kingston Reif of the RAND Corporation, a former US deputy assistant secretary of defense, also warned that without the predictability of the treaty, each side could be incentivized to plan for the worst or increase their deployed arsenals to show toughness and resolve.
Putin has repeatedly brandished Russia's nuclear might since sending troops into Ukraine in February 2022, warning Moscow was prepared to use 'all means' to protect its security interests. In 2024, he signed a revised nuclear doctrine lowering the threshold for nuclear weapons use.
The New START Treaty, signed in 2010 by US President Barack Obama and his Russian counterpart, Dmitry Medvedev, was originally supposed to expire in 2021 but was extended for five more years. The pact envisioned sweeping on-site inspections to verify compliance, although they stopped in 2020 due to the COVID-19 pandemic and never resumed.
In February 2023, Putin suspended Moscow's participation, citing US inspections of its nuclear sites at a time when Washington and its NATO allies have declared Moscow's defeat in Ukraine as their goal. However, the Kremlin emphasized it wasn't withdrawing from the pact altogether, pledging to respect its caps on nuclear weapons.
Putin offered in September to abide by New START's limits for a year to buy time for negotiations on a successor agreement, warning that the pact's expiration would be destabilizing and could fuel nuclear proliferation.
Rose Gottemoeller, the chief US negotiator for the pact and a former NATO deputy secretary-general, said extending it would serve US interests. She argued that a one-year extension of New START limits would not prejudice any vital steps the US is taking to respond to the Chinese nuclear buildup.
Previous pacts, such as SALT I in 1972 and the Anti-Ballistic Missile Treaty in 1972, have been terminated or modified, leading to increased tensions and strategic competition. The Intermediate-range Nuclear Forces Treaty, signed in 1987, was also terminated in 2019, leading to concerns about the potential for a new arms race.
Trump's proposed Golden Dome missile defense system has worried Russia and China, with Kimball warning that they may respond by building up their offensive weapons to overwhelm the system.
Trump's statement about US intentions to resume nuclear tests for the first time since 1992 also troubled the Kremlin, which last conducted a test in 1990. Kimball warned that a US resumption of tests would blow a massive hole in the global system to reduce nuclear risk, prompting Russia to respond in kind and tempting others to follow suit.
The world is heading toward accelerated strategic competition, with more spending and increasingly unstable relations involving the US, Russia, and China on nuclear matters, according to Kimball. He warned that this could mark a potential turning point into a much more dangerous period of global nuclear competition.
