The Wall Street Journal -President Donald Trump kept world leaders guessing for a second day on what he is going to do about the Iran nuclear accord after describing it this week at the United Nations as “an embarrassment” to the U.S.

But the options facing his administration aren’t as simple as staying in the deal or leaving it. Administration officials have gamed out multiple scenarios for options both at home and abroad. ?

At home, Congress is a wild-card in some of these scenarios because if lawmakers choose to “snap back” U.S. sanctions that had been lifted as part of the nuclear deal, it could touch off a series of reactions leading to the collapse of the deal.

Abroad, a disparate group of international powers who are part of the nuclear deal form a challenging target for negotiations: Iran, Russia, China and three European nations—the U.K., France and Germany.

Secretary of State Rex Tillerson and other officials are urging Mr. Trump to certify Iran’s compliance to Congress and stick with the accord, but to make changes to address U.S. concerns with it, according to current and former U.S. officials. That could include amending the Iran Nuclear Review Act so that Mr. Trump doesn’t have to keep certifying Iran’s compliance to Congress every 90 days, as the act requires. The next deadline is Oct. 15.