But what about getting back in?

“If the Biden administration wanted to rejoin the treaty, he could do it, but it would be cumbersome,” said Peter Jones,  who helped negotiate the treaty .

Peter Brookes, a senior research fellow at the conservative Heritage Foundation, said he’s against a last-minute reprieve.

“We haven’t seen enough change in Russian behavior,” said Brookes, a Defense Department official under former President George W. Bush. “If there’s a Biden administration in January, they can look at this and decide whether they agree or disagree with the Trump administration’s decision.”