In the alternate reality of U.S. policy debate, nothing is what it seems. Words get twisted, motives hidden, and basic principles of cause and effect are ignored. This is never more true that in the current furor over U.S. policy toward our enemies.
On the one hand we have "Iraq war critics" (i.e., the partisan Left) which shamelessly repeats the oldest logical error in existence:
A is a member of B + A is also a member of C = All C are B
thereby generalizing any misdeed by any member of the U.S. military into a condemnation of the entire military, up to and including its Commander in Chief.
On the other hand we have the Administration, unwilling to defend itself against these smears, for it knows that merely stating what is reasonable and necessary would only aggravate these critics' attacks. In the alternate reality of U.S. policy debate, explaining how sausage is made risks having sausage outlawed.
Between these hands stands John McCain. Not often inclined to fits of the vapors, he nonetheless wants to create a fixed, arbitrary bound on what treatment of POWs is permissible and what is not. He justifies this position in terms of global politics, but that can be refused as easily as the argument for a hard ban on firearms: to coin a phrase, "if torture is outlawed, only outlaws will use torture".
No, the real currency that McCain possesses is his history as a tortured POW. Understandably, he didn't like it. Understandably, he does not wish to believe that what he endured could ever be justified. Apparently, he has generalized his experience to cover any torture under any circumstance.
Fortunately, you and I are not tortured POWs, so we can step back and be more objective. Some dare say that torture is never effective. We need look no further than Guy Fawkes, whose arrest and torture revealed the conspiracy that attempted to blow up the British King 400 years ago this month, to refute. Others dismiss the information gleaned by torture, saying that you can get anyone to say anything. That may be true, but only devalues subjective information. Facts which can be verified or disproved are quite another matter, especially if the subject knows that disproved facts will only lead to another round of torture. Still others say that torture is no more effective than other, less cruel forms of interrogation. That may also be true when time is not a factor; but when it is, torture is better. Building up a relationship and wearing down a subject can take weeks or months. Depending on the subject, it may have zero chance of working in hours or minutes. If a WMD attack is hours away, any technique which has no chance of getting timely information is definitely inferior to one which has even a small chance.
Does that mean that I am not repelled by the torture endured by our POWs? Of course not. I am repelled, in part because of my patriotism, in part by my empathy, but in the greatest part by my distain for the motives of the Viet Cong. They did not torture because they needed information. Our POWs knew little of strategic value, and even if they did, that knowledge would have quickly aged into worthlessness. Despite that, they were often continued to torture for many years. Clearly, the Viet Cong were not after factual information. They tortured either out of simple cruelty, or out of a desire to coerce false statements and behaviors for propaganda. Since I do not find either of those motives compelling, I disapprove of the use of torture to serve them.
McCain and others complicate the discussion by stating that, unless we unconditionally outlaw torture, we risk undermining the Geneva Convention, putting the safety of our own soldiers at risk. But the Geneva convention is not a unilateral statement of policy. Rather, it is a straightforward quid-pro-quo. It defines a certain class of combatant, and says in effect, "I will treat your combatants of that class a certain way, with the understanding that you will do the same for my combatants of the same class." The teeth of the agreement are hidden, but essential: combatants which do not qualify as members of the class with be treated worse; and if you treat my qualified combatants worse than specified, I will do the same to yours. Without this unspoken understanding, the agreement protects nothing.
In fact, I would argue that the Geneva convention is a highly-overrated piece of paper. In the case of "uncivilized" enemies, its central assumption is clearly false: such enemies do not care how their prisoners are treated. Stalin had his returned POWs imprisoned or shot; Al Qaeda celebrates dead soldiers as martyrs, and sends many of them on suicide missions. Such enemies respond to our solicitude not with gratitude, but with contempt for our weakness. As for "civilized" enemies: if we are obliged in the name of decency to provide Geneva Convention protections unilaterally, are they not obliged to do that same? What value the agreement then?
I would even argued that, if the Geneva Convention does has any value, and we expect it to protect our future POWs, then we should never offer G.C. protections to any combatant who does not completely qualify for them. If we instead offer such protections unilaterally, we may actually encourge "semi-civilized" opponents to cheat the rules of war, since they know that so doing will not imperil their own POWs held by the U.S.
So: does this mean that Congress can not regulate our treatment of non-qualifying combatants? Certainly not - but a much more nuanced approach is required than anyone has yet proposed. We need to create various categories for such combatants; define "probably cause" criteria for belonging in each category; specify who has the authority to adjudicate the categories; and define the treatment which is permitted within each category. It is fine to define a category where illegal combatants receive "Geneva-lite" treatment... but there must also be a category where everything up to and including chemical interrogation and physical torture is permitted, should that prove necessary to save the lives of millions. Decency should be maximized for every category, of course... but decency heavily tempered by logic and reality.