Ending Iran’s nuclear-weapons program may be President Trump’s top goal for stabilizing the Middle East, but his biggest test lies in Syria. Ahmed al-Sharaa, the former rebel who overthrew the Assad regime four months ago, presides over a weak interim government that can’t control all of Syria’s war-torn territory. While the Israelis have put the south under their power umbrella, the Turks have forces in the north and are backing Mr. Sharaa. Tensions are mounting between Ankara and Jerusalem over how to promote security and stability in the region.
Mr. Trump hinted at what’s at stake on April 7, when, sitting beside Prime Minister Benjamin Netanyahu in the White House, he offered to mediate. “Any problem you have with Turkey, I think I can solve,” Mr. Trump told the prime minister. But, he added, “you have to be reasonable.”