U.S. President Donald Trump has all but decided to withdraw from the 2015 Iran nuclear accord by May 12 but exactly how he will do so remains unclear, two White House officials and a source familiar with the administration’s internal debate said on Wednesday. There is a chance Trump might choose to keep the United States in the international pact under which Iran agreed to curb its nuclear program in return for sanctions relief, in part because of “alliance maintenance” with France and to save face for French President Emmanuel Macron, who met Trump last week and urged him to stay in, the source said. A decision by Trump to end U.S. sanctions relief would all but sink the agreement and could trigger a backlash by Iran, which could resume its nuclear arms program or “punish” U.S. allies in Syria, Iraq, Yemen and Lebanon, diplomats said. […]