I don't think you ever had an Afghan surge, did you? Maybe I missed it.
Your situation in Afghanistan was much like what we had in Northern Ireland during the Troubles. An ongoing misery that you felt duty-bound to continue with. And also, the other options were possibly worse.
Now we see what the other options entail for you (and us) by doing things differently. I don't expect it will be pain-free. They will certainly be bad for a lot Afghanistanis.
But I do understand walking away. Because now we see who they are, there was no saving them. They are their own enemy.