That's exactly what the pending hearings will sift out...by a vote of a panel or jury. That's how American Law works, or didn't you know?
The Bush Administration has defined terrorist in such a way as to include themselves in the definition. A terrorist, in their definition, is someone who has caused or has potential to cause great harm to american citizens as a result of their actions.
Therefore there is ample evidence to prosecute them. Ordering torture is so blatant an act of hubris and defiance of the Geneva Convention, that is a setup for assuring future retaliations not only against our armed personelle, but also our citizens.
When you have people strapping bombs to their bodies and blowing themselves up in desperation, a little torture isn't going to be an effective "lesson" for them to abide by. Predictably, by anyone smarter than a brain-dead garden slug, they will use it to further fuel anti-american sentiments (imagine that? 
) and put us in graver danger.
So, therefore, having put americans in jeopardy and in the way of harm, they have de facto and wilfully exacerbated terrorism against our armed servicepeople and US Citizens. It is imperative of the Congress, as custodians not only of the People but also of the military to formally and visibly (due to the visible nature of the defiance) prosecute these crimes accordingly.
It's all very simple.
