This latter point may well be valid, as an inspection of the Conventions reveals. The most basic key to understanding the Conventions is to be aware that they are treaties. Treaties are not laws; they are agreements subject to enforcement under the law, like contracts. If you suffer through a class on international law, the central principle of treaty law is usually expressed with the needlessly pretentious Latin pacta sunt servanda: pacts must be kept.
Why is this important? Because the Geneva Conventions, like all contracts, make clear to whom and under what circumstances they apply. They state explicitly that they apply to any powers that have signed them, and that both detainers and detainees are subject to their dictates. This is not pedantic; this is quite basic to treaty law, and the Geneva Conventions are treaties. A treaty is between two countries that sign it; if it's violated by either one, it is void. To argue that a treaty applies to a country or group that didn't sign it, or that it continues to apply to one country after the other has violated it, is not being idealistic or morally upright - it is simply being silly, and unjustifiably claiming firm legal authority for a purely moral position.
An analogy might be instructive. My friend Bob and I decide to sign a peace treaty with one another, stating that we will take no action that would harm the other under any circumstances. Now Bob shoots me, but I refuse to retaliate; I gave my word that I would not harm him, and my word is binding. Now, that's a laudable moral position, and would do wonders to make me look like the good guy in this exchange, but does the treaty require it? No, of course not. Bob violated the treaty. It's gone.
Just to demonstrate that I'm not blowing smoke, here's the text of the First Convention, which is repeated for each of the other three (it's from a preamble of sorts):
"Although one of the Powers in conflict may not be a party to the present Convention, the Powers who are parties thereto shall remain bound by it in their mutual relations. They shall furthermore be bound by the Convention in relation to the said Power, if the latter accepts and applies the provisions thereof."
Let's apply this concretely to the Al'Qaeda situation. We will make the rather large assumption that we have some reason to believe Al'Qaeda has "accepted and applied the provisions" of the Geneva Conventions, and is therefore subject to protection under it. Let's start with an individual operative, whose captivity is governed by the Third Convention. When captured, he is immediately BOUND to share with us his name, rank (what rank? In what organization? But I digress), date of birth, and serial number (repeat digression). Now, I think it would be fair to assume that most captured operatives don't comply with this rule. Let's see what the Convention says about that scenario:
"If he wilfully infringes this rule, he may render himself liable to a restriction of the privileges accorded to his rank or status."
This is the kind of cause-and-effect clause common to treaties. Assuming an Al'Qaeda operative had a rank or status we could use to determine what privileges the Convention grants him, the Convention itself states he doesn't get them if he doesn't cooperate. Simple. Straightforward.
Now let's go broader and deal with the Al'Qaeda organization as a whole. Say, again, that we had made them honorary signatories to the Conventions (despite their being neither a state nor an internationally recognized polity). That would certainly include the Fourth Convention, which applies in detail to the treatment of Civilians and Non-Combatants, but we needn't even read that far; again, the preamble lays out some "bare minimum" rules by which all parties must conduct themselves:
"(1) Persons taking no active part in the hostilities, including members of armed forces who have laid down their arms and those placed hors de combat by sickness, wounds, detention, or any other cause, shall in all circumstances be treated humanely, without any adverse distinction founded on race, colour, religion or faith, sex, birth or wealth, or any other similar criteria.
To this end the following acts are and shall remain prohibited at any time and in any place whatsoever with respect to the above-mentioned persons:
(a) violence to life and person, in particular murder of all kinds, mutilation, cruel treatment and torture;
(b) taking of hostages;
(c) outrages upon personal dignity, in particular humiliating and degrading treatment;
(d) the passing of sentences and the carrying out of executions without previous judgment pronounced by a regularly constituted court, affording all the judicial guarantees which are recognized as indispensable by civilized peoples."Al'Qaeda and other paramilitary groups have violated every single one of these injunctions, made videos, broadcasted the world, and declared their pride in (and intent to repeat) these actions. They have killed unarmed civilians en masse; they have taken civilian hostages, humiliated them, degraded them, and executed them without trial. Assume we had some reason to call them a state. Assume we had some reason to believe they would abide by this document. Assume that they meet any of the many conditions required to be protected by it. They have violated its most basic precepts, and the text is clear: this is a treaty, and therefore either mutually binding or not binding at all. In case you don't believe me, try this line from the Fourth Convention:
"Nationals of a State which is not bound by the Convention are not protected by it."
You read that correctly. The unarmed civilian populace of a state not signatory to the Convention are not protected by it. This, more than anything, makes it clear that Jon Stewart's argument cannot rest on the Geneva Conventions; they are not statements of incontrovertible principle, but mutually binding contracts with numerous qualifiers.
Again, I support Jon's moral position, and his categorical rejection of torture. But for him to attempt to ground this position in the Geneva Conventions is not only naive, it is intellectually dishonest. The text of the Conventions is widely available and written in accessible language; there is no excuse for arguing that they are statements of principle and ideology that apply to us no matter what our enemies do. That's the Declaration of Independence. This is a treaty.
Stewart's ethics are laudable, and I believe as he does that the United States should be of strong moral character no matter the consequences. But May was right; he has drawn a totally personal moral line with no basis in the Conventions, and it is plain wrong not to admit it.
EDIT: Commenters on this and the corresponding Reddit post have argued that if Al-Qaeda isn't governed by the conventions, they should still be subject to treatment as citizens of the states in which they're taken. That might have some validity depending on the nature of our conflict with that state, if any; I have to look at it more, but I wonder. If we captured Taliban militants, would they count as Pakistani nationals, and benefit from the treaty signed by the government they're attacking?