Originating from diplomatic security measures enacted during the First World War, DSS was formally established in 1985 following the deadly 1983 bombings of the U.S. embassy and Marine barracks in Beirut, Lebanon. It is the leading U.S. law enforcement agency abroad and the most widely deployed in the world, protecting 275 U.S. diplomatic missions in over 170 countries and 29 U.S. cities. As employees of the U.S. State Department, DSS special agents are unique in U.S. federal law enforcement for also being members of the Foreign Service.
