Five-decade nuclear restraint ends as US–Russia ‘New START’ treaty expires today

Washington (The Uttam Hindu): Today marks a highly sensitive and historic moment for global security, as the final major treaty limiting nuclear weapons between the United States and Russia has formally expired. With the end of the New Strategic Arms Reduction Treaty (New START) on February 5, 2026, there are now no legally binding limits on the strategic nuclear arsenals of the world’s two largest nuclear powers for the first time in nearly 50 years.

The expiry means that intercontinental ballistic missiles, submarine-launched missiles, and strategic bombers operated by both countries are no longer subject to treaty-based caps. Security experts have warned that this development poses a serious risk to international stability and increases the chances of a renewed arms race.

Russia says it is no longer bound by limits

Following the treaty’s expiration, Russia announced that it is no longer obligated to follow any restrictions on nuclear weapons agreed with the United States. In a statement issued on Wednesday, the Russian Foreign Ministry said Washington failed to respond to President Vladimir Putin’s proposal to extend the treaty’s conditions for another 12 months.

The ministry said its concerns were deliberately ignored, leaving Moscow with no reason to continue complying with the treaty’s requirements or mutual transparency measures. Russia described the situation as a direct outcome of a lack of cooperation from the United States.

What was the New START treaty

The New START agreement was signed in 2010 by then US President Barack Obama and Russian President Dmitry Medvedev. Its main goal was to limit the deployment of strategic nuclear weapons capable of destroying major military and industrial targets within minutes.

The treaty came into force in 2011 and was extended in 2021 by the Joe Biden administration for five years, setting its expiration date in 2026. The agreement was part of a broader nuclear arms control framework dating back to the Cold War, beginning with the SALT accords in the 1970s and followed by START-I, START-II, and the Moscow Treaty. With New START ending, that decades-old structure has now collapsed.

UN and experts warn of rising nuclear risks

The United Nations has described the treaty’s end as a “critical moment” for international peace and security. UN Secretary-General António Guterres warned that, for the first time in more than half a century, nuclear superpowers are operating without formal restraints, with the risk of nuclear weapon use at its highest level in decades.

Pope Leo also urged both countries to move away from fear and mistrust and prioritize shared global interests. Security analysts, including Matt Korda of the Federation of American Scientists, have cautioned that both the US and Russia could now significantly expand their deployed nuclear forces, potentially pressuring other countries, including China, to accelerate their own nuclear build-up.

US and Russia hold over 90 percent of nuclear weapons

As of January 2025, Russia possessed around 4,309 nuclear warheads, while the United States had approximately 3,700—together accounting for more than 90 percent of the world’s nuclear arsenal. With the treaty no longer in effect, both countries can increase missile numbers and deploy hundreds of additional strategic warheads.

Although US President Donald Trump has indicated he may consider a future agreement involving China, the world has, for now, entered a new and more dangerous phase without a formal nuclear arms control framework.