Kabul International Airport

The top U.S. military officer called the 20-year war in Afghanistan a "strategic failure" and acknowledged to Congress that he had favored keeping several thousand troops in the country to prevent a collapse of the U.S.-supported Kabul government and a rapid takeover by the Taliban.

Explosions and gunfire rang out as the Taliban attacked Kabul airport July 17 in the militants' latest attempt to steal the initiative with the country in the grip of a presidential power struggle.