ANTAKYA, Turkey - The rebel commander was nervous. He had changed phone numbers and been difficult to reach before finally agreeing to meet in Antakya, a city near the border with war-torn Syria that has long swarmed with rebels, refugees, and spies. On the road to an out-of-the-way hotel, he told the driver to avoid the main route through town. "It’s better not to drive among all the people," he said.