US stops sharing nuclear arms data with Russia under START Treaty

The United States has told Russia it will cease exchanging detailed data on its nuclear weapons stockpiles, the White House said, calling the move a response to Russia’s suspension of participation in the New START nuclear arms treaty.

While Russian President Vladimir Putin has not formally withdrawn from the treaty, his suspension from participating in it announced in February has endangered the last pillar of US-Russian nuclear arms control.

The US and Russia hold nearly 90 percent of the world’s nuclear warheads – enough to destroy the planet several times over. The New START (Strategic Arms Reduction Treaty) limits the number of strategic nuclear warheads countries deploy.

“Russia has not been in full compliance and refused to share data which we … agreed in New START to share biannually,” John Kirby, the US National Security Council spokesperson, told reporters in a conference call on Tuesday.

“Since they have refused to be in compliance … we have decided to likewise not share that data,” he said.

“We would prefer to be able to do (this) but it requires them being willing to as well.”

Kirby made it clear that the data would only be shared again when Russia was also ready to do so.

“The US and Russia…are obligated to exchange comprehensive databases twice a year. We offered to continue reciprocal implementation of this obligation. Unfortunately, Russia informed the US that it will not engage in this data exchange due to its purported suspension of this treaty,” Vedant Patel, deputy spokesperson for the US State Department said at a press conference.

Under the terms of the New START, signed in 2010 and due to expire in 2026, Moscow and Washington may deploy no more than 1,550 strategic nuclear warheads and 700 land- and submarine-based missiles and bombers to deliver them.

Under the treaty’s “Biannual Data Exchanges”, Moscow and Washington provide a declaration of deployed strategic delivery vehicles, launchers and warheads, including a breakdown of warhead numbers deployed across the three types of delivery vehicles – air, sea and land-based.

The treaty, which then-Presidents Barack Obama and Dmitry Medvedev signed in 2010, also envisaged sweeping on-site inspections to verify the US’s and Russia’s compliance.

But inspections have been dormant since 2020 because of the COVID-19 pandemic. Discussions on resuming inspections were supposed to have taken place in November 2022 but Russia abruptly called them off, citing US support for Ukraine.

In February, Russia formally suspended its participation in the treaty. Putin stated that his step was not an exit from the agreement. He said Russia wanted to continue to adhere to the agreed upper limits for nuclear weapons for the time being.

The White House, which has previously accused Russia of multiple violations of the treaty, has said Russia’s refusal to comply is “legally invalid” and the decision to withhold the nuclear data is yet another violation.