The Third Geneva Conventions set forth rules of warfare, and in particular to bind signatories to common obligations in the treatment of prisoners of war. Nations signing the treaty are entitled to have their captured combatants treated humanely by other signatories, and in return must provide the captured combatants of signatories with the same standard of humane treatment. If one of the signatories breaks the Treaty by not obeying the rules, then the treaty no longer applies. That’s a fair deal that encourages compliance. Since al Qaeda is not an arm of any state signing the Treaty, and in any case does not abide by the rules set forth by the Treaty, they should not qualify for protection under the Treaty, but the US Supreme court has ruled they do.