THE FOUNDATIONS OF GLOBAL NUCLEAR SAFETY ARE COLLAPSING – AN ARMS RACE COULD FOLLOW

The collapse of the last US-Russia nuclear treaty later today risks prompting an unconstrained new arms race.

The expiry of the New Strategic Arms Reduction Treaty (New START) ends almost half a century of binding limits on US and Russian nuclear stockpiles. Through various treaties since the 1970s, the two biggest nuclear powers have – despite their differences – found a common ground, agreeing that nuclear restraint is necessary. That was, it appears, until now. 

What comes next is “a less predictable world”, said Mallory Stewart, chief executive of the Council on Strategic Risks. That comes amid an intensifying nuclear landscape: there are now at least 12,341 nuclear weapons in existence, and this number is going up, among more volatile rhetoric, including recent statements about resuming nuclear testing.

Experts suggest the end of New START, the last bilateral arms control treaty capping Washington and Moscow’s strategic nuclear stockpiles, could increase the risk of an unconstrained nuclear arms race. But the immediate danger is the loss of nuclear oversight and predictability in an arena where miscalculations could prove catastrophic.

“We do not know how fast or in what systems nuclear arms racing between the US and Russia will proceed,” Stewart told The i Paper. But one thing is evident: “More nuclear weapons mean more nuclear risk globally.”

Cornerstone of arms control

Signed in 2010 by former US president Barack Obama and former Russian president Dimitri Medvedev, New START was a continuation of the START I treaty that expired in 2009. It reaffirmed mutual restraint by capping strategic nuclear arms at 1,550 deployed warheads and enabling mutual inspections. Though still a significant amount of arms, it was dramatically lower than Cold War levels.

US President Joe Biden and Russian leader Vladimir Putin extended the treaty for another five years in 2021, but Russia suspended its participation two years later after its full-scale invasion of Ukraine but continuing to observe limits. “If it expires, it expires,” Donald Trump said last month, suggesting that another extension was unlikely, even though Putin floated a one-year continuation.

“This may also be largely political in that the treaty is seen as an Obama treaty, which Trump doesn’t want to support,” Stewart, who previously served as the Assistant Secretary for the Bureau of Arms Control, added.

Despite confusion over the exact time the treaty ends, arms control experts have suggested this would be 11pm today, midnight in Prague, where the treaty was signed.

Experts believe a return to Cold War-era levels, peaking at 70,000 warheads in the 80s, is unlikely even with the collapse of New START. But the stakes are still high.

Russia is estimated to have 4,309 nuclear warheads, the US 3,700, China 600, the UK 225 and France 290, according to the Federation of American Scientists.

Sahil Shah, Senior Policy Adviser at the Institute for Security and Technology, put it this way: “The more realistic risk is unmanaged competition.”

“New START didn’t stop modernisation of nuclear arsenals,” Shah said. “But it provided a floor against strategic freefall by sustaining habits of transparency and professional contact that helped both sides understand the other’s capabilities and activities.” Without that framework, competition does not disappear, but it becomes “harder to interpret and easier to misjudge”.

The effects may be felt globally, as it “raises escalation risks in Europe and complicates crisis and conflict management across alliances”, said Shah, prompting nuclear powers like the UK and France to re-evaluate positions on nuclear weapons and deterrence. Regions like East Asia were particularly exposed regarding nuclear proliferation because “extended deterrence debates there are sensitive to perceived credibility and predictability”, Shah added.

New nuclear playing field

Some experts argue that bilateral agreements born after the Cold War are not necessarily effective in the modern nuclear landscape. The US and Russia still hold around 86 per cent of the world’s nuclear weapons. But China is rapidly expanding its arsenal, adding roughly 100 warheads each year, and shows little appetite for joining trilateral arms control agreements.

“The arms control architecture was a product of a previous time, bipolar superpower competition and then a post-Cold War unipolar moment of US dominance. This is no longer the era we live in,” Dr Laura Considine, Associate Professor of International Politics at the University of Leeds, told The i Paper. Evolving global diplomacy, Nato tensions and US volatility could also inform what comes next, at a time when trust, predictability and nuclear oversight become even more important.

“The spread of nuclear weapons to other countries is less impacted by New START and more by concerns over the reliance of the US as an ally or by concerns over possible further Russian aggression in Europe,” said Dr Considine. Despite this, some agreements have endured: the Non-Proliferation Treaty (NPT), for example, has 191 signatories agreeing not to pursue nuclear proliferation, indicating that there is still a desire to work towards a nuclear-free world despite expiring treaties and uncertainty.

Looking ahead, Shah said it was the responsibility of all nuclear-armed states to prevent another arms race. “Their choices set the strategic baseline that others react to – whether they intend to or not.” Future developments may also call on other players to take the lead. Stewart suggests efforts by the permanent members of the UN Security Council to discuss “preventing the risks of miscalculation, misunderstanding, and unintentional escalation” would force the US and Russia to participate.

In the meantime, however, today indeed marks a new nuclear chapter, one that analysts are approaching with caution.

“The incentive to avoid catastrophic miscalculation hasn’t disappeared,” Shah said. “The most realistic progress lies in preserving predictability where possible, keeping dialogue alive, and avoiding demands that make engagement impossible.”

“That’s not idealism — it’s managing nuclear risks in a messy era of strategic instability while formal arms control is rethought.”

2026-02-04T12:45:59Z