I am one of those people who oppose Gitmo. I don't want America to fail. I love America as much as any person who lives there.
But in a proper society, the ways in which we deal violence upon our foes and upon terrorism suspects are limited. We prohibit torture. Even in Israel, a country where arguably the threat of terrorism and foreign attack is more imminent than in the United States, acts of torture are generally prohibited by law except in some very, very distinct cases of ticking-bomb terrorists - and Israel is not a free country by any means.
In a proper society, the military is subordinate to the civilian power. The spies and special operatives and Men in Black are not in charge. Reporters, legislators, and voters are in charge.