US considers expanding nuclear arsenal, resuming underground testing: report

The administration of US President Donald Trump is considering expanding Washington's nuclear arsenal and potentially resuming some form of underground nuclear testing after the expiration of the last major US-Russia arms control treaty, according to a report published on Monday by The New York Times.

The newspaper said that the recent statements from senior officials suggest Washington is reviewing options to deploy additional nuclear weapons and preparing for possible renewed testing, steps that would mark a significant shift from decades of US policy aimed at limiting and reducing deployed warheads.

The report followed the expiration of the New START treaty, which had capped the number of deployed strategic warheads for both the US and Russia at about 1,550. Trump declined an informal extension proposed by Russian President Vladimir Putin while the sides considered negotiating a replacement accord.

On February 5, he said Washington should seek a “new, improved and modernised” nuclear arms control agreement rather than extending the New START with Moscow.

Thomas DiNanno, the State Department’s undersecretary for arms control and international security, told a disarmament forum in Geneva that the expired treaty had placed “unilateral constraints” on Washington and said the US is now free to strengthen nuclear deterrence.

Options include expanding existing forces and activating non-deployed nuclear capabilities if directed by Trump.

One potential step involves reactivating missile tubes on the US Navy Ohio-class submarines that had been disabled to comply with treaty limits, allowing additional nuclear-armed missiles to be deployed at sea.

Some experts believe such moves could be intended to pressure Russia and China into new arms control negotiations, while others warn they could instead trigger a broader arms buildup.

DiNanno also addressed nuclear testing, offering the first detailed explanation of Trump’s earlier call to resume testing “on an equal basis” with Russia and China.

He suggested Moscow and Beijing may have conducted smaller, hard-to-detect nuclear explosive tests, including a suspected Chinese test in 2020, though an international monitoring network reported no detection at the time.

Jill Hruby, former head of the National Nuclear Security Administration, told the newspaper the administration’s intentions remain unclear.

Terry C. Wallace, former director of Los Alamos National Laboratory, also expressed surprise at the certainty of claims about foreign testing, the report said.

The US last conducted a full-scale nuclear explosive test in 1992.