(3) which constitutes a violation of common Article 3 of the international conventions signed at Geneva, 12 August 1949, or any protocol to such convention to which the United States is a party and which deals with non-international armed conflict; or
(3) which constitutes a grave breach of Common Article 3 as defined in subsection (d) when committed in the context of and in association with an armed conflict not of an international character; or
And who gets to decide what constitutes a "grave breach" as opposed to a mere violation? Why King George, of course!
(3) INTERPRETATION BY THE PRESIDENT.—(A) As provided by the Constitution and by this section, the President has the authority for the United States to interpret the meaning and application of the Geneva Conventions
So basically, the Geneva Conventions can go screw themselves. We're gonna torture whoever the hell we please, because we're America, and we're always right. But nobody better even think about torturing our soldiers or we'll bomb them into the Stone Ageand then prosecute 'em for war crimes.