"It is a busy time for diplomacy in the Trump White House, what with them planning the North Korea summit, weighing what to do about Syria, and a state visit with [French President Emmanuel] Macron next week," John Oliver said on Sunday's Last Week Tonight. And on top of that, Trump faces a massive decision on whether to re-certify the Iran nuclear deal — and there's a growing sense that this time, Trump will actually kill the agreement on May 12. Trump has made no secret of his disdain for the agreement, signed by former President Barack Obama, Iran, China, Russia, Britain, Germany, France, and the European Union, but its demise "could have huge, lasting consequences," Oliver said.