I was always a fan of going in there after 9/11, kicking ass, then getting out. Instead we've stayed 16 years, lost over 2,000 American lives, suffered more than 20,000 wounded, spent countless billions of dollars, and gotten a corrupt government, incompetent Afghan troops and absolutely nothing else for our efforts.
Long past time to go. If they act up again, we can go back and kick ass again and leave again - repeat as necessary. Otherwise, leave this poor miserable country to its fate.