Many saw the post-Cold War 1990 – 91 Gulf War as motivated by U.S. oil interests , though it reversed the hostile invasion of Kuwait . After the September 11 attacks in 2001 , questions of imperialism were raised again as the United States invaded Afghanistan ( which harbored the attackers ) and Iraq ( which the U.S. incorrectly claimed had weapons of mass destruction ) . The invasion led to the collapse of the Ba'athist government and its replacement with the Coalition Provisional Authority . The Iraq War opened the country 's oil industry to US firms for the first time in decades and arguably violated international law . Both wars caused immense civilian casualties
September 11 attacks
September 11 attacks
American imperialism