In the absence of a formal declaration of war, what are we going to do with this sucker?
Conspiracy to kill Americans, conspiracy to commit a terrorist act, conspiracy to obtain and use a weapon of mass distruction, a few charges I know I've forgotten....probably conspiring with the enemy (treason) and possibly conspiring with a foreign power to kill Americans (treason).
Absent a formal declaration of war, he's most likely going to be tried in exactly the same way he would be if there were a formal declaration of war.
You won't hear Congress say anything about it...this lack of a formal declaration of war aided the president in that it expedited matters in Afghanistan, and aided Congress in that many of them hoped Afghanistan would turn out to "be another Viet Nam" , so Congress needed it's collective political butt covered in order to be free to gloat....which of course hasn't happened, LOL.