October 7 marks the 11th anniversary of the beginning of the U.S.-led war in Afghanistan.

It has lasted longer than any other war in U.S. history. More than 3,000 international coalition troops have died in the war, including 2,000 Americans. Far more Afghan civilians have died.

The war was triggered by the terrorist attacks on the United States on September 11, 2001. Less than a month later, U.S. troops were on the ground in Afghanistan, attacking al-Qaida militants and the ruling Taliban government that hosted the terrorist organization.

The Taliban was quickly routed, but the militant insurgency has grown in strength over the years.

The U.S. and international troops have been plagued in recent months by a series of so-called insider attacks – assaults on Western troops by Afghan soldiers and police.

Coalition troops have begun pulling out of Afghanistan. All foreign combat troops are scheduled to be gone by the end of 2014.

The U.S. and NATO say Afghan forces will be capable of taking over the fight against the Taliban after 2014. However, many analysts predict a bloody new multi-factional civil war.