Last Nuclear Arms Treaty Between the US and Russia Ends, Raising Global Fears

The last major treaty limiting nuclear weapons between the United States and Russia has officially come to an end, opening the door to a new and dangerous arms race. The agreement, known as New START, expired on February 5 after both countries failed to extend it or agree on a replacement. With its expiration, the world has lost its final safety net designed to keep the two largest nuclear powers in check.

Signed in 2010, New START was created to prevent the worst case scenario, a large scale nuclear war. Under the treaty, Washington and Moscow were required to limit their deployed nuclear warheads to 1,550 each. The deal also allowed both sides to inspect each other’s nuclear facilities, helping to build trust and reduce the risk of deception.

This was not the first such effort. The original arms control agreements began in 1991, when the limit was set at 6,000 warheads a number that was gradually reduced over time. New START represented the final chapter of decades of nuclear restraint.

Death of New START: U.S., Russia enter uncharted territory as last nuclear arms control deal expireshttps://t.co/cTh1t2MnXj pic.twitter.com/ASjJ8VNyfc
— The Washington Times (@WashTimes) February 5, 2026

Now, that chapter has closed.

Russia’s presidential aide Yuri Ushakov said Moscow would continue to seek stability through diplomatic channels. However, Russia’s Foreign Ministry made it clear that the country no longer considers itself bound by any treaty limits and is free to decide its next steps.

So far, both nations have largely stayed within the agreed limits. But without a binding deal, that restraint may not last.

According to the Stockholm International Peace Research Institute (SIPRI) Yearbook 2025, Russia currently possesses about 5,459 nuclear warheads, while the United States holds around 5,177. These numbers highlight how much destructive power already exists and how quickly the balance could shift.

Experts warn that the real danger lies not just in more weapons, but in less transparency. Without inspections and data sharing, both sides may begin to guess each other’s intentions. History shows that such guesswork can turn small misunderstandings into major crises.

UN Secretary General Antonio Guterres described the moment as a serious threat to global peace, urging both countries to return to the negotiating table without delay.

This is not an isolated setback. Several other key defense agreements between the US and Russia have already collapsed in recent years, including treaties that limited tanks and troop levels in Europe.

Now, global attention is focused on upcoming international conferences in April and May, where nuclear armed states will be expected to explain how they plan to protect the world from catastrophe.

For many observers, the question is no longer whether the nuclear age is changing, but whether the world is ready for what comes next.