Geneva Conventions don't apply to terrorists . . .
. . . says Thomas Sowell in this article.

Neither the criminal law nor the rules of the Geneva Convention are suited to terrorism. International terrorism is an act of war without a formal declaration of war by the sovereign nation that is sponsoring the terrorists. Terrorism is not simply a domestic crime, even when it occurs within our borders. Nor are the terrorists soldiers, as defined in the Geneva Convention.

Terrorist organizations cannot operate without state support somewhere. In fact, al Qaeda has state sponsorship. One state sponsor was Afghanistan, but others remain. (Saudi Arabia is high on my list.) Thus, our terrorist enemies are conducting warfare by proxy against us on behalf of the state sponsors/ But because their methods, targets and organization and insignia fail to meet lawful criteria of the Conventions, the terorists themselves have no rightful claim to the protection of the Conventions.

Captured terrorists are not simply breakers of domestic American law. They are unlawful combatants in acts of war, and therefore may and should be properly handled in a summary manner.