Well, the bilateral US-Afghan security treaty would bar filing in an Afghan court; in the US realm, you would have standing problems, the Baker bar, and sovereign immunity. If I recall -- and IANAL, let alone a nat-sec attorney -- there's some Fourth Circuit precedent that could justify stripping sovereign immunity from individual officials in jus cogens violations, but I don't think anyone else takes that seriously.

The bitter truth is that there's not much you can do in those circumstances. To paraphrase the Melian Dialogues, the strong do what they will and the weak take what they're given.