More than two years after U.S. President Donald Trump quit the multinational nuclear deal with Iran, his administration is risking a crisis at the United Nations by threatening to reimpose international sanctions that were eased under that accord.

It’s a threat that could produce an outcome that once was unthinkable: pushing allies such as Germany and France to side with Russia and China in the U.N. Security Council, leaving the U.S. isolated.

The conflict may begin with a vote in the council this week on a U.S. resolution to make permanent an international ban on arms deals with Iran that’s due to expire in October. If the U.N. fails to act, Secretary of State Michael Pompeo said in a tweet on Sunday, it "will make a mockery of its mission to maintain ‘international peace and security.”