Those goals have largely been accomplished. Plausibly, we should now diminish our troop presence in Afghanistan and turn our attention to other strategic concerns. Opportunities beckon as the Arab and Muslim worlds are in a transition that may mark the beginning of a turn away from jihadism. So also are major risks approaching in the rise of Iran and its maturing nuclear weapons program.
Yes. Years ago. The last five or so have been to establish a "US friendly" government there, which has been mostly a waste of time, money, men and material. At best we have an entity that is little better than what we have relations-wise with Pakistan, and we've recently all seen how that really works.
Iran is a problem, and is probably sooner than later going to be a big problem, and wasting our blood and treasure trying to fix failed states weakens us for those battles to come.