Just curious - what would such a "guarantee" from a Gitmo prisoner look like ?
Cross your heart?
Swear on the Bible?
Pinkie swear?
Cut your palms and exchange blood?
Meanwhile, if the US doesn't keep Obama's end of the bargain, it'll give the bad guys a rallying cry to blow us up. It does seem that the Taliban were more honorable negotiators than Obama's negotiators were.