Expiration of US-Russia Agreement Could Trigger Rapid, Dangerous Nuclear Arms Race, New Report Warns

This is especially alarming given President Trump's recent statements asserting that neither laws nor traditional morals will limit his use of presidential power. Such an expansive view of executive authority increases the risk that nuclear policy decisions could be driven by unilateral impulses and makes arms control agreements like New START more important than ever.

Both countries already possess the technical capacity to rapidly increase the number of nuclear weapons ready to launch, according to a new analysis by the Union of Concerned Scientists (UCS), "Nuclear Weapons Without Limits? Avoiding a New Arms Race After New START."

With existing stockpiles, the United States and Russia could deploy hundreds of additional warheads in a matter of weeks. "New START has been one of the most effective tools for reducing nuclear weapon dangers and preventing costly, destabilizing arms racing," said Jennifer Knox, report author and policy and research analyst at UCS. "The United States and Russia already have enough deployed nuclear weapons to kill tens of millions of people in less than an hour. Letting New START lapse will erase decades of hard-won progress and make the world less safe."

New START currently caps deployed strategic nuclear warheads at 1,550 for each country. The Treaty is the latest in a series of agreements that reduced the US arsenal from a peak of more than 30,000 warheads in the 1980s. While Russia suspended some treaty validation measures in 2023, both countries have continued to comply with the treaty's limits, highlighting their shared interest in stability and restraint.

But if New START expires, that could all change. Within weeks, the United States could field another 480 nuclear weapons at bomber bases. Within months, it could load almost 1,000 additional nuclear warheads onto submarines. And within years, it could load an additional 400 nuclear warheads onto land-based missiles. Russia could do the same, increasing the stakes of political tension and the possibility of deeply catastrophic miscalculations.

"Both Russia and the United States already have more than enough nuclear weapons to devastate each other many times over," Knox said. "Adding more to the mix increases the chances of an accident, and the consequences of miscalculation or escalation."

In addition to the security risks, there is also an enormous financial cost of a renewed nuclear competition. Preparing and deploying additional warheads would add to the Pentagon's already over-budget and behind-schedule nuclear modernization program, diverting resources from urgent domestic needs without providing any increase in U.S. security.

Additionally, a U.S.-Russia arms race could also pressure other nuclear armed states, including China, to expand their nuclear arsenals, further undermining global security.

The report urges the United States to accept Russia's offer to continue honoring New START's limits for one year after the treaty expires while negotiations on a future agreement proceed, arguing that maintaining these limits would help cap nuclear dangers, preserve strategic stability and buy critical time for diplomacy.

"The United States is safer when it leads with restraint and cooperation, not when it races to build more nuclear weapons," said Knox.