Russia-US nuclear pact set to end in 2026 and we won’t see another

In February 2026, for the first time in decades, there will be no active treaty limiting the size of U.S. and Russian nuclear arsenals. Experts are divided on whether the New START treaty has truly made the world safer, but they are far more in agreement on one thing: a replacement is unlikely.

The United States and Russia first agreed to limit their nuclear weapons and allow each to inspect the other’s stockpiles with the START I treaty in 1991, and this was followed by New START in 2011. In 2021, Joe Biden and Vladimir Putin agreed to extend the treaty for five years. It is due to expire on February 5 and negotiations over its replacement have failed.

Tensions between Russia and the United States had already escalated when the former staged a full-scale invasion of Ukraine in 2022. A few months later, Russia withdrew from weapons inspections, prompting the United States to return the favor. Today, both states are talking about a resumption of nuclear testing – bellicose theater with no practical purpose. A replacement for New START seems more unlikely than ever.

Mark Bell of the University of Minnesota says a new treaty capping the number of U.S. weapons at a level similar to Russia’s is unlikely to please the United States, which fears it will need enough to deter Russia and China simultaneously. China has 600 nuclear weapons, far fewer than the 5,000-plus held by the United States and Russia, but it is rapidly expanding its arsenal. At the same time, Russia is unlikely to accept a cap that would follow this argument and seek to allow it to bomb fewer bombs than the United States. And China will not want to be drawn into a new deal if it caps its bombs at current levels, thereby preventing possible parity with Russia and the United States. Treaties are never easy, but it’s a tricky place to start, Bell says.

START I and New START were widely considered a success. They are certainly not perfect, but they exert a pragmatic and stabilizing influence. But Bell wonders if they’ve actually done much to make the world safer. “Did they save both superpowers a little money? Maybe. Did they provide a useful forum for cooperation? Yes. But did they fundamentally change the likelihood of war? I don’t think so,” he says.

With or without a treaty, there will always be a real risk of nuclear war, Bell says. In many ways, the threat of mutually assured destruction is the best insurance we have now that the atom has been split, and it is the unthinkable outcomes of nuclear conflict rather than treaties that actually prevent wars, he says. “The stabilizing effect comes from danger, and you can’t get rid of it. It’s a feature, not a bug, of nuclear deterrence,” he says.

But some privileged experts are more concerned about the end of the treaty. Stephen Herzog is an academic at the Middlebury Institute of International Studies in Monterey, California, but previously worked on arms control at the U.S. Department of Energy. He said New scientist Put simply, losing the New START treaty makes nuclear war more likely.

“It makes the world less secure because of the lack of transparency, because it allows for unbridled competition from leaders who seem to want to rely on nuclear weapons,” Herzog says. “In a situation where Russia is increasingly unpredictable, and in a situation where the United States administration is unfortunately increasingly unpredictable, not having a vital confidence-building and transparency measure that essentially curbs the arms race really scares me.”

There are still a few treaties covering nuclear weapons. The ambitious Treaty on the Prohibition of Nuclear Weapons aims to eradicate them completely and is attracting signatories – but especially not among the nuclear powers. Several nuclear states have signed the Treaty on the Non-Proliferation of Nuclear Weapons, but this does little to limit the number of bombs in existence. Only New START has truly held the nuclear superpowers accountable.

Herzog believes that if Donald Trump and Putin wanted to, they could immediately agree to a substantially similar deal. Indeed, Putin suggested, which was warmly received by Trump, that an informal one-year extension could be agreed. But no negotiations have taken place and such an agreement would be, at best, a short-term solution to the problem.

Philipp Bleek of the Middlebury Institute of International Studies says continuing the treaty could be helpful if the extra time was used to negotiate a new treaty, but the prospects for long-term arms control are dim. “The one-year extension could make the Russians feel like they’ve given up on the issue and could make them less inclined to engage. [in future talks]”, says Bleek.

Treaty negotiations are complex struggles involving politicians, militaries and spy agencies, with opportunities to put small but potentially life-saving strategic advantages in the fine print, Herzog says. Many key personnel — weapons inspectors, negotiators and nuclear experts — have been fired, fired or encouraged to resign by the Trump administration, he says, which could give Russia the upper hand.

“If we were to go to work and try to negotiate a new treaty, I think there are some things we probably don’t have the personnel to do,” Herzog says.