The most recent Amnesty Internation report called the detention centers down in Guantánamo the gulag of our time." This New Republic article does a good job of showing side-by-side comparisons of actual Gulags and Guantánamo.

It concludes, very reasonably:

The detention center at Guantánamo is legally dubious and has been a public relations disaster for the United States. The treatment of certain prisoners in Iraq and Afghanistan has been far worse. Amnesty's president Irene Kahn says that these practices are "undermining human rights in a dramatic way." Her outrage is valuable and essential. If only she could express it without employing obscene moral parallels.

Yes, that's about right. Now, I don't have a problem with harsh criticism of Guantánamo. It is legally, as well as morally, dubious. And we should be held to a higher standard with regard to human rights than, for example, the former Soviet Union. But you also have to keep things in perspective, and when you lose that, you lose credibility.