United States invasion of Afghanistan occurred after the September 11 attacks in late 2001 , supported by close US allies . The conflict is also known as the U.S. war in Afghanistan . 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 . The United Kingdom was a key ally of the United States , offering support for military action from the start of preparations for the invasion . It followed the Afghan Civil War 's 1996 – 2001 phase between the Taliban and the Northern Alliance groups , although the Taliban controlled 90 % of the country by 2001 . The U.S. invasion of Afghanistan became the first phase of the War in Afghanistan ( 2001 – present )
September 11 attacks
September 11 attacks
United States invasion of Afghanistan