As the U.S. and allied militaries invaded Afghanistan in the months following September 11, 2001, they fought primarily against the Taliban, a radical Islamic political group that had ruled the country since 1996.
Primarily made up of members of the ethnic Pashtun tribes, the Taliban allowed other Islamic militant and terrorist groups to train and operate within Afghanistan including both Al Qaeda and Chechen rebels.
U.S. forces fought against these groups as well as the Afghan Military Forces (AMF).