A chilling prospect looms as the US-Russia nuclear weapons treaty, New START, is set to expire on Thursday, igniting fears of a renewed arms race. This treaty, signed in 2010, was a critical pillar in preventing nuclear catastrophe, capping strategic nuclear warheads for both nations at 1,550 and establishing transparency measures. Its expiration marks the end of an era, a time when arms control cooperation between Washington and Moscow helped bring an end to the Cold War.
Pope Leo, in a powerful statement, urged the renewal of this treaty, emphasizing the need to "do everything possible to avert a new arms race" in our current global climate. The original START treaty, signed in 1991, had set a higher limit of 6,000 nuclear warheads for the US and the Soviet Union. New START, a successor agreement, was signed in Prague in 2010, by the US and Russia, the Soviet Union's successor state. Despite a technical suspension three years ago, both countries have largely adhered to the treaty's terms.
The treaty's expiration follows a worrying trend. Other longstanding arms control treaties have already crumbled, including the Intermediate-Range Nuclear Forces Agreement, which significantly reduced the deployment of shorter-range nuclear weapons in Europe, and the Open Skies Treaty, which allowed unarmed reconnaissance flights over signatory territories for military force monitoring. The Conventional Armed Forces in Europe Treaty, limiting tanks, troops, and artillery systems within Europe for Russia and NATO forces, has also fallen by the wayside.
Admiral Sir Tony Radakin, Britain's former head of the armed forces, warns that the architecture that kept the world safe is now "at risk of unravelling." In a speech last year, he described the collapse of these treaties as one of the most dangerous aspects of our current global security, alongside "the increasing prominence of nuclear weapons."
Dmitry Medvedev, the Russian politician who signed the New START treaty in 2010, stated that its expiration should "alarm everyone." This is a stark comment from a figure whose recent rhetoric has included nuclear threats. In contrast, US President Donald Trump has appeared less concerned, stating to the New York Times, "If it expires, it expires... We'll just do a better agreement."
Washington believes that any future arms control treaty should include China, which has been expanding its nuclear arsenal. Meanwhile, Russia argues for the inclusion of France and the UK, Europe's nuclear powers, in any future agreements.
Darya Dolzikova, a senior researcher with RUSI's Proliferation and Nuclear Policy Programme, expressed concern over the expiration of New START, noting "drivers on both sides to expand their strategic capabilities." Both the US and Russia are modernizing their nuclear forces and increasing strategic capabilities, with a new arms race already underway.
Dolzikova highlights Russia's concerns about penetrating US air defenses, which have only intensified with Trump's "Golden Dome" plan to protect North America from long-range weapons. In response, Russia has developed new weapons designed to overcome air defenses, including the Poseidon torpedo and the Burevestnik cruise missile, both intercontinental, nuclear-armed, and nuclear-powered.
The US, Russia, and China are also developing long-range hypersonic missiles capable of maneuvering at speeds over 4,000 mph, making them harder to intercept. Dolzikova warns that these expanding military capabilities will make reaching a new arms control treaty even more challenging, especially with the "growing salience of nuclear weapons" as a deterrent for more, not fewer, countries.
The US and Russia appear unhurried to sign a new arms control treaty, with the subject only briefly discussed during Russian President Vladimir Putin's meeting with Trump in Alaska last year. While a new deal is still possible, the expiration of New START signals a more volatile and dangerous era.
