The Second Gulf War began in March 2003 with the invasion of Iraq by a multinational force. The invasion of Iraq led to an occupation and the eventual capture of Saddam Hussein, who was later executed by the Iraqi Government. Violence against coalition forces and among various sectarian groups soon led to asymmetric warfare with the Iraqi insurgency, strife between many Sunni and Shia Iraqi groups, and al-Qaeda operations in Iraq. Evidence of war crimes committed and sanctioned by the United States Department of Justice created controversy globally, and helped dispel the notion of the United States as a liberating force in the War of Terror. Member nations of the Coalition withdrew their forces as public opinion favoring troop withdrawals increased and as Iraqi forces began to take responsibility for security. In late 2008, the U.S. and Iraqi governments approved a Status of Forces Agreement effective through to the end of 2011. The Iraqi Parliament also ratified a Strategic Framework Agreement with the U.S., aimed at ensuring international cooperation in constitutional rights, threat deterrence, education, energy development, and other areas. In 2009, U.S. President Barack Obama announced an 18-month withdrawal window for "combat forces".