The Northern Alliance and NATO-led ISAF invaded Afghanistan on October 7, 2001, and overthrew the Al-Qaeda-supportive Taliban government. Troops remained to install a democratic government, fight a slowly escalating insurgency, and to hunt for Al-Qaeda leader Osama bin Laden who was killed by American troops 10 years later, on May 2, 2011. On December 31, 2016, NATO forces officially ended combat operations in Afghanistan; withdrawal has been announced for September 11, 2021.