Its a war. Noone won. Everyone lost.
The Americans lost a lot of money funding the war (yes guys, that worldwide crisis IS your fault, and i'ts tied directly to that war), leave alone a lot of good guys and girls to roadbombs, suicidebombers, rocketstrikes and whatnot.
The Iraqi and Afghans lost even more ... anyone needs that explained?
Even us 'cowardly' euros lost, coz in the end we paid part of that war due to the artificial difference in value between the euro and the dollar, and the ensuing crisis.
If anyone can point out a clear winner (even if it were some false political ideal like 'democracy' ... but that went out the window for a system of state control over the citizenry, which is quickly starting to resemble what the communists did in russia before the fall of the wall) ... please let me know, i'm still looking.
You can discuss whether it was necessary or not, but even necessary war means everyone loses.
No, pulling out isnt the 'honorable' thing to do (then again, honor was a medieval concept thought up to keep the knights from raping every semi-decent looking farmgirl they ran across unpunished, or sleep with the king's wife ... it barely has any place left in our rotten society built on self-interest). It only serves one purpose : save more american lives which would otherwise be lost for no good reason at all. It's also an admission of making the wrong choices ...
If you have to go 'liberate' a country from a bunch of hardline extremist muslims that you installed and armed yourself during the cold war, because even the Russians wouldnt be able to beat them (and honestly, the communist russians were a LOT better at those things than the US troops will ever be due to no moral restrictions whatsoever), thats obviously a wrong choice after a wrong choice.
If you have to invade a country under false pretenses, just to get their oil, after arming them yourselves during the Iran-Iraq war 'to help them stop the extremist muslims' ... thats a wrong choice after a wrong choice.
It takes a very brave man to admit to those things, and an even braver man to prefer saving lives over saving face. It takes a stupid man to believe bravery is standing firm in the face of impossible odds. And yes, impossible they are, coz you CAN NOT push the red button, and you cant win against guerilla fighters that can ignore all rules of engagement while you have to adhere to them.
But that's just the opinion of a damn euro who has no clue whatsoever, of course 
When speaking your mind, it is of utmost importance to keep using it !