First, just war is not the issue before us (and for the record I'm not a proponent of just war theory). The issue before us is an ethical issue: we're debating how we should handle detainees, not whether this war is just or unjust.
How one treats another human being, whether the treatment is by an individual or by a government, is per se a question of ethics. And your reply indicated that 3000 deaths justified any retribution metted out by our government or those acting on behalf thereof. Whether it's legal or not is not the issue: whether it's morally right or wrong is.
So by Thomist I'm talking about how a Christian applies Aristotelian ethics....Nicomachean ethics....to the situation at hand, nothing more.
I'm certainly not framing this in a just war context which, btw, the Iraq war would certainly not be endorsed by either Augustine or Aquinas given indisputable fact that this was and is a pre-emptive war courtesy of "The Bush Doctrine."
Anyway, Thomas' ethics are the lens through which I'm looking at the problem, not Thomas' just war theory. Of course, you're free to do as you wish, whether that be sticking to your utilitarian analysis (yes, you are doing just that) or trying to wedge this entire Middle East venture into a just war framework when only one piece can be justified under the doctrine (Afghanistan).