Sen. John McCain Monday became the highest-ranking U.S. official to enter Syria since the bloody civil war there began over two years ago, The Daily Beast has learned. McCain, one of the fiercest critics of the Obama administration’s Syria policy, made the unannounced visit across the Turkey-Syria border with Gen. Salem Idris, the leader of the Supreme Military Council of the Free Syrian Army. He stayed in the country for several hours before returning to Turkey. Both in Syria and Turkey, McCain and Idris met with assembled leaders of Free Syrian Army units that traveled from around the country to...