What does the end of US-Russia nuclear arms treaty mean for disarmament?

For 15 years, the New Start treaty bound the United States and Russia to curb their nuclear arsenals – until it expired earlier this month. Researcher Benoit Pelopidas tells RFI what hope remains for disarmament now that there are no longer fixed limits on the world's two largest nuclear powers.

In what could mark a major turning point in the history of arms control, New Start expired on 5 February. Neither US President Donald Trump nor his Russian counterpart Vladimir Putin has shown interest in renewing it. 

The treaty was signed between the United States and Russia on 8 April 2010 and came into force on 5 February 2011. Initially planned to last 10 years, it was extended for another five in 2021.

Its goal was to limit each side to 800 missile launchers and 1,550 nuclear warheads, with the two countries authorised to inspect each other's stockpiles.

It was never a global treaty. Other countries signed up to the broader Treaty on the Non-Proliferation of Nuclear Weapons (NPT), which came into force in 1970 and now has 191 parties, including the US and Russia.

But Washington and Moscow also had bilateral arms control agreements in place continuously since 1972 – until now, notes Benoît Pelopidas, an expert on nuclear threats at Sciences Po university in Paris.

"But it would be false to deduce from that that the arms race has not started yet and might start now," he tells RFI. 

"There are reasons to think that the arms race started as early as the spring of 2010."

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'Possible acceleration'

Even before New Start expired, implementation of the treaty deteriorated over time, culminating in Russia suspending its participation in 2023.

"And now we're at a full level where it's no longer implemented at all," says Pelopidas. "It's new diplomatically, and it enables the possible acceleration of an ongoing arms race."

NATO called for "restraint and responsibility" after the treaty expired.

"Russia's irresponsible nuclear rhetoric and coercive signals on nuclear matters reveal a posture of strategic intimidation," an official told French news agency AFP, speaking on condition of anonymity.

"NATO will continue to take the measures necessary to ensure its credibility and the effectiveness of its overall deterrence and defence position."

The Kremlin had proposed continuing to comply with New Start's limits until February 2027, but the White House did not respond.

Moscow considers the treaty's expiration "a negative development", Russian presidential spokesman Dmitry Peskov told reporters. "We express our regret in this regard."

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Disarmament still possible

According to Pelopidas, disarmament is possible and has been partially achieved before, especially in the early 1990s after the end of the Cold War. 

"In 1991, we had 58,000 nuclear weapons on the planet. And we're now at a level of roughly 12,000 in 2025, which is a massive decrease," he says. 

"We have, between 1986 and today, dismantled or retired over 80 percent of the existing arsenal in the world. So it is not materially impossible to dismantle or disarm."

The world's remaining nuclear stockpile still has the potential to wreak huge destruction, he stresses, a fact that he believes should drive all nuclear powers to work towards de-escalation.

"If the theory of nuclear winter is correct, a so-called limited nuclear war between India and Pakistan that led to the explosion of 100 Hiroshima-sized bombs – that is, roughly 1 percent of the existing arsenal – would lead to the death of 2 billion people by starvation due to its indirect consequences over two years," Pelopidas says.

"That's how destructive the capacity of the existing arsenal is."

Episode mixed by Erwan Rome.