Key dates in U.S. involvement in Afghanistan since Sept. 11, 2001

FILE PHOTO: U.S. Army Soldiers assigned to the 10th Mountain Division stand security at Hamid Karzai International Airport, Kabul, Afghanistan, in this photo taken on August 15, 2021 and released by U.S. Navy on August 18, 2021. U.S NAVY/Central Command Public Affairs/Sgt. Isaiah Campbell/Handout via REUTERS

(Reuters) - The last U.S. troops flew out of Afghanistan, fulfilling President Joe Biden's pledge to bring an end to America's longest war after a chaotic and violent evacuation from Kabul, the U.S. military said on Monday.

The following is a chronology of U.S. involvement and major developments in Afghanistan over the past two decades: