What’s at Stake If Trump Kills the Nuclear Deal With Iran?

Donald Trump will announce today whether the U.S. will leave the Iran nuclear deal, with consequences likely to be felt from Middle East war zones to oil markets. If the U.S. president refuses to keep waiving sanctions under the six-nation accord reached in 2015, there’s a chance Iran will also walk away and resume its atomic program. European powers have pressed Trump to preserve the agreement while they negotiate side-deals to address his main concerns. A breakthrough has so far remained elusive. So what’s at stake if the U.S. withdraws?