Perhaps the most anxious man in the room was Khaled Mashal, the leader of the militant Palestinian faction Hamas and a repeated target of Israeli assassination attempts. Two years earlier, agents from Israel’s Mossad spy service had jabbed Mashal with a poison needle on an Amman street a few miles from where he now stood. He survived only after a furious King Hussein prevailed on the Israelis to provide his doctors with an antidote.