Key events in Afghanistan War:

Oct. 7, 2001 _ U.S. and British forces begin airstrikes in Afghanistan after the Taliban refuse to hand over al-Qaida leader Osama bin Laden, blamed for the 9/11 attacks.

Nov. 13, 2001 _ Taliban fighters abandon Kabul after weeks of air assaults. About 1,300 U.S. troops involved in offensive.

Dec. 7, 2001 _ Taliban stronghold Kandahar falls. Bin Laden and Taliban leader Mullah Mohammed Omar escape.

June 13, 2002 _ Hamid Karzai is elected as head of state of a new interim government by the loya jirga, or grand council.

August 2003 _ NATO deploys troops to Kabul for a peacekeeping mission. The force later expands to other areas and numbers 11,000. The U.S. has more than 10,000 troops in Afghanistan.

Jan. 4, 2004 _ Council of elders ratifies a new constitution, making Afghanistan an Islamic state with a strong president.

Oct. 9, 2004 _ Karzai wins Afghanistan's first presidential election.

September 2008 _ Extremist attacks have made this the most violent year since the 2001 U.S.-led invasion began, with at least 120 U.S. troop deaths and 104 from other NATO nations. There are now 31,000 U.S. troops in Afghanistan.

Jan. 30, 2009 _ Shortly after President Barack Obama's inauguration, there are 36,000 U.S. troops in Afghanistan. NATO forces total 32,000.

Feb. 17, 2009 _ Obama approves adding some 17,000 U.S. troops in Afghanistan.

May 11, 2009 _ Top U.S. general in Afghanistan, Gen. David McKiernan, is replaced as Obama tries to turn around the stalemated war.

June 9, 2009 _ First deployment of Marines moves into Afghanistan; by June 9, more than 10,000 are in place to ramp up operations against the Taliban.

Sept. 21, 2009 _ Gen. Stanley McChrystal, the top U.S. and NATO commander in Afghanistan, says in a confidential report that without additional forces, the war against insurgents will end in failure.

Oct. 20, 2009 _ Karzai bows to intense U.S. pressure and agrees to a runoff election, acknowledging he fell short of a majority after U.N.-backed auditors stripped him of nearly a third of his votes. Two weeks later his challenger drops out of the race, and Karzai is declared the winner.

October 2009 _ October becomes the deadliest month with 58 U.S. troops killed. Officials expect Obama to make a decision soon to deploy 32,000 to 35,000 more U.S. forces.