US and Russia Reach Informal Nuclear Understanding

The United States and Russia have stepped back from the brink of a renewed nuclear arms race by agreeing to informally maintain the limits of the New START treaty, despite the agreement’s official expiration earlier this month.

New START Officially Expires

Signed in Prague in 2010, the New START treaty capped deployed strategic nuclear warheads and delivery systems held by Washington and Moscow, while establishing detailed inspection and verification regimes. The treaty formally expired on 5 February 2026, bringing an end to the last remaining legally binding framework restraining the world’s two largest nuclear arsenals.

With its expiration, the final Cold War–era pillar of nuclear arms control effectively fell away.

An Informal Brake on Escalation

Despite the absence of a formal extension, both sides opted to preserve the existing numerical limits. Kremlin spokesman Dmitry Peskov said talks held in Abu Dhabi showed that Washington and Moscow were prepared to take “responsible positions” and move quickly toward new negotiations.

While no legal agreement is in place, officials from both countries signalled a shared commitment to maintaining the nuclear status quo until a broader and updated deal can be reached.

Trump Pushes for Broader Deal Including China

US President Donald Trump has argued that any future arms control framework must be more modern and comprehensive than New START. A key condition for Washington is the inclusion of China in negotiations.

US officials have accused Beijing of conducting covert nuclear tests and are pressing for a trilateral framework aimed at boosting transparency. China, however, has so far resisted joining formal talks, complicating prospects for a new agreement.

Inspections End, Uncertainty Grows

Although an informal restraint mechanism is now in place, New START’s inspection and verification system has officially lapsed. Experts warn that the absence of on-site inspections and data exchanges could fuel mistrust and increase the risk of miscalculation over time.

Analysts say that without a legally binding framework, the current arrangement remains fragile and vulnerable to political shifts in both capitals.

From START to New START

The arms control process began in 1991 with the original START treaty between the United States and the Soviet Union, which limited each side to fewer than 6,000 nuclear warheads. Following the collapse of the Soviet Union, that agreement was eventually replaced by New START in 2010.

With New START now expired, the global nuclear order rests on an informal understanding—one that preserves stability for now but leaves the future of arms control deeply uncertain.