Syria, officially the Syrian Arab Republic, is a country in western Asia.
Syria, along with the Far East, Europe, North Africa, Iran and Pakistan, was one of the places guessed by Tony Stark to be the probable location of the Mandarin's broadcast signal when J.A.R.V.I.S. factored in available A.I.M. downlink facilities, until being informed by J.A.R.V.I.S. that the actual location was Miami, Florida.
Cybertek sent many of its shipments related to the Centipede Project and the creation of the Deathlok Soldiers to many countries around the globe, including Syria, in order to hamper their tracking while they were re-routed to the Barbershop Headquarters in Cuba.
Antoine Triplett managed to identify many of them, learning that their destination point was in Havana, letting Phil Coulson and his team guess where John Garrett established his base once he revealed himself as a HYDRA operative.
A Special Ops unit, including Will Simpson, was tasked with finishing a mission in the Syrian capital of Damascus. During the mission Simpson consumed specialized amphetamines known as Combat Enhancers to greatly increase his endurance and pain tolerance. To combat the effects of these drugs, Simpson was also given supplementary drugs; a stabilizer to prevent his body from shutting down, and a depressant to return his body chemistry to normal levels. Misuse of the pills led to a catastrophe during the mission.