Advocates of the nuclear deal with Iran are convinced the pact is in mortal danger following Republican Donald Trump’s upset election.

Deal skeptics on Capitol Hill have already prepared a raft of bills that have a far better chance of making it into law with the threat of a White House veto now out of the way. But the president-elect himself can just as easily send what he’s called a “disastrous” deal to the dustbin of history by simply refusing to sign off on sanctions relief.

“That’s why I find it so hard to believe that the deal survives,” said Richard Nephew, a former State Department sanctions official who now heads the program on Economic Statecraft, Sanctions and Energy Markets at Columbia University. “At some point, [Trump] will have to make an affirmative decision to support its implementation.”

Under the deal, the United States isn’t scheduled to provide additional sanctions relief until October 2023, well into a second Trump term. But the deal does require the president to periodically extend waivers on sanctions that remain on the books, as long as Iran abides by its obligations under the deal.