The U.S. military on Sunday shot down a Syrian Air Force fighter jet that bombed local forces aligned with the Americans in the fight against Islamic State militants, an action that appeared to mark a new escalation of the conflict.
The U.S. had not shot down a Syrian regime aircraft before Sunday's confrontation, said Navy Capt. Jeff Davis, a Pentagon spokesman. While the U.S. has said since it began recruiting, training and advising what it calls moderate Syrian opposition forces to fight IS that it would protect them from potential Syrian government retribution, this was the first time it resorted to engaging in air-to-air combat to make good on that promise.