A secret State Department cable has concluded that the Syrian military likely used chemical weapons against its own people in a deadly attack last month, Foreign Policy reported Tuesday, January 15. American diplomats in Turkey conducted an intensive investigation into claims that Syrian President Bashar Assad used chemical weapons, and made what an Obama administration official who reviewed the cable called a “compelling case” that Assad’s military forces had used a deadly form of poison gas in the city of Homs on Dec. 23. The use of chemical weapons by the Assad regime would cross the “red line” President Barack Obama first established last August. Many officials believe that Assad is testing U.S. red lines. “This reflects the concerns of many in the U.S. government that the regime is pursuing a policy of escalation to see what they can get away with,” an official said.