The founding fathers were fed up with injustices in the old world and established the USA on a set of principles including the right to confront one's accusers, the right to a defense, the right to legal counsel, the right to a speedy trial by jury, basic human rights to decent treatment while in detention, and the right of non-self incrimination. The Guantanamo and other similar facilities fly in the face of the entire premise for the founding of the USA.
If we cannot convict these people, then they must be freed. Not detained. Freed and deported. Better another building goes down than we abandon our principles. In a war of ideals, the one who abandons his ideals first for the illusion of safety loses. That would be the USA that is the loser here. We're the big guys with the big powers and we have been acting like a bunch of frightened little girls.
Furthermore, those responsible for tossing our ideals overboard, authorizing torture, and callously profiteering from the confusion are traitors and must be brought to justice or there will be a next time and we cannot afford a next time.