During the occupation of Iraq U.S. intelligence and military services contracted CACI International Inc, a U.S. company in Virginia, to provide "intelligence services" in Abu Ghraib prison near Baghdad. CACI employees were directly involved in torturing Iraqi prisoners.
The U.S. army recently contracted CACI for "intelligence analysis services" in Syria. The Syrian government has not invited or otherwise allowed U.S. military or its contractors within its country. Any such activities infringe on Syrian sovereignty and are thereby in violation of international law.
Islamic State media just released video from inside a camp in Jordan which shows U.S. personal providing military and intelligence training to anti-Syrian-government "rebels". This suggests that the Islamic State penetrated, one way or another, a U.S. training camp in Jordan. It thereby benefits from such U.S. military training and intelligence activities in and around Syria.