The White House is crafting a Middle East strategy for the remaining 18 months of President Barack Obama ’s term that would more forcefully address conflicts in Iraq, Yemen and Syria amid tensions over the conclusion of talks with Iran. U.S. and Iranian negotiators narrowed some key differences for completing a deal that would scale back Tehran’s nuclear program in exchange for lifting economic sanctions. The talks face a Tuesday diplomatic deadline, but the two sides remained at odds on Monday over several critical elements. Any reorientation of Mr. Obama’s Middle East strategy would test the durability of his broader foreign-policy doctrine, and senior administration officials said the president is intent on cleaning up leftover messes in the region before leaving office in 2017, including relations with key allies that have been strained by the Iran talks. White House officials see the conclusion of Iran talks as a gateway […]