"The United States has been attempting to change Iraq's regime since the 1991 Persian Gulf war, although achieving this goal was not declared policy until 1998. In November 1998, amid a crisis with Iraq over U.N. weapons of mass destruction (WMD) inspections, the Clinton Administration stated that the United States would seek to go beyond containment to promoting a change of regime. A regime change policy was endorsed by the Iraq Liberation Act (P.L. 105-338, October 31, 1998). Bush Administration officials have emphasized regime change as the cornerstone of U.S. policy toward Iraq since shortly after the September 11, 2001, attacks, well before the launch of Operation Iraqi Freedom on March 17, 2003."
CRS Report for Congress, RL31339
United States. Dept. of State. Bureau of Public Affairs. Foreign Press Centers: http://fpc.state.gov/