AFGHANISTAN: After the 9/11 attacks, Congress passed the Authorization for Use of Military Force Against Terrorists, authorizing the President "all necessary and appropriate force against the nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001." This act resulted in the 2001 invasion of Afghanistan, in President George W. Bush's broader Global War on Terrorism. The objective of the 2001 invasion, known as Operation Enduring Freedom, was to remove the Islamic fundamentalist Taliban lead government from power in Afghanistan, and to capture top level al-Qaeda leaders, including its founder Osama bin Laden. The invasion, fought in conjunction with the US's NATO allies, began on October 7, 2001, quickly leading to the overthrow of the Taliban government and implementation of Hamid Karzai as Afghanistan's interim president. In early 2002, after the Battle of Tora Bora and success with Operation Anaconda, the United States began focusing on military intervention in Iraq, shifting military and intelligence resources away from Afghanistan in War on Terror, with U.S. Secretary of Defense Donald Rumsfeld stating in May 2003 that the "major combat" in the conflict was over.
In the attempt to quell the Taliban insurgency in southern Afghanistan, more than 1,000 insurgents and 150 ISAF troops were killed in the two-month operation, being the bloodiest period since the start of the war in 2001. With ISAF assuming complete command of security forces in Afghanistan in October 2006, the U.S. saw mounting skepticism from European allies over the war at the 2006 Riga summit.