Ten years ago today, the United States launched an air assault on Osama bin Laden's training camps in Afghanistan.
The offensive started with the goal of ousting the Taliban and destroying al Qaeda. But what initially looked like an easy victory became the longest war in American history.
While the Taliban no longer rules the country, they haven't given up.
Insurgents remain able to pull off high profile attacks, like the one that took place outside the U.S. Embassy in Kabul in September this year.
"The insurgency still has very strong teeth and it continues to use them at quite a number of occasions," said German Brig. Gen. Carsten Jacobson, a spokesman for coalition forces.
The cost of the war is taking its toll. More than 2,700 troops have been killed in the fighting - 1,780 of whom were Americans.
"You're away from your family. You go do hard things every day, then you come back, and you rest, and you do it over again," U.S. Army 1st Lt. Christian Gehrels said.
There's no doubt the U.S. is making progress in the war. Bin Laden is dead and many of the leaders al Qaeda are on the run.
But there's still one task that is proving harder to accomplish: creating an honest government that Afghans can believe in and defend.
"I don't see this war subsiding or being won or lost in the next several years. I think it's going to continue," said Seth Jones, a political scientist with the RAND Corporation.
But many military leaders on the ground in Afghanistan disagree, saying the end is near.
"I can tell you that by December 2014 they will have the ability to take the lead for security here in Afghanistan," U.S. Army Lt. Gen. William Caldwell said.
"On a personal level, I think the fight in Afghanistan is still relevant," Gehrels remarked. "Everyone understands what Afghanistan was, and why we came here."
About 98,000 service men and women are now fighting in Afghanistan.
President Obama says 33,000 of those troops will come home by next summer. He added that there'll be a full withdrawal two and a half years after that.
The pressure will then be on Afghanistan's own security forces to keep the country secure.
"In the future, if Afghanistan does become more than a third world country, I'll be able to say, I helped to do that," Pfc. Jacob Williams, 21, said.