Fifteen years after the US invasion of Afghanistan, President Barack Obama and the American military have dug in for a long campaign that defies rigid timelines and easy barometers of victory. On October 7, 2001, in response to the 9/11 attacks, President George W. Bush launched Operation Enduring Freedom to dislodge the Taliban and capture or kill al Qaeda militants they were harbouring.
For much of the 15 years since, the US has groped for a strategy - flitting between trying to chase down jihadis, take accursed terrain, stand up a fragile government or beat back a dogged Taliban insurgency. Obama came to office in 2009, promising a war-weary US electorate that he would bring the troops home. But, after a series of missed deadlines and some semantic gymnastics about the definition of combat, he finally abandoned his pledge during his last year in office.