The WWII camps that held POWs were run under the Geneva Convention (1929 version), which, among many articles, provided that prisoners must be allowed a certain amount of space, air, and other personal freedoms.
Guantanamo Bay, in contrast, was not governed by the rules of the Geneva Convention for many years. In 2001, President George W. Bush signed an executive order that the U.S. military may lawfully detain any non-citizen involved in international terrorism. The Bush administration claimed that these terrorist suspects -- unlawful combatants who operated without a uniform -- were not protected by the Geneva Convention. That is, they were not recognized as lawful soldiers.
