The
War in Afghanistan (or the
American war in Afghanistan) is the period in which the United States invaded
Afghanistan after the
September 11 attacks. Supported initially by close allies, they were later joined by
NATO beginning in 2003. It followed the
Afghan Civil War's 1996–2001 phase. Its public aims were to dismantle
al-Qaeda and to deny it a safe base of operations in Afghanistan by removing the
Taliban from power. Key allies, including the United Kingdom, supported the U.S. from the start to the end of the phase. This phase of the War is the
longest war in United States history.