Quote Originally Posted by Dayuhan View Post
Is it possible for us to ensure the legitimacy of someone else's government?
That would be, IMO, the 'No.'
...our actions were calculated not to establish legitimacy in the eyes of the Afghans but to establish legitimacy in the eyes of our own populace and an international audience.
That would be the 'yes', with a tag-on that the bulk of our political effort is always expended internally; our domestic politics drive our international actions to a very significant extent -- and to the confusion of the rest of the world.

This is the crux of the issue:
...how - short of going back in time and doing it all differently - do we undo what we've done and move back to some course that has some reasonable chance of generating a legitimate government that has reasonable prospects of surviving and that will not give aid and comfort to our enemies?
It shows the flaw of predicating international action on domestic party politics -- a condition that is unlikely to change in the near term. However, it deserves an answer and that answer has to unhappily be that we cannot. We will leave and what happens will happen. It will not all be for naught but it will have been far more costly in all terms than it needed to be simply because we ignored your first question and the US domestic concern drove the second ...