the U.S. Department of Justice claimed that habeas corpus—a legal recourse against unlawful detention—did not apply to Guantanamo Bay because it was outside of U.S. territory.
The Bush administration maintained that it was not obliged to grant prisoners basic protections under the U.S. Constitution or the Geneva Conventions, since the former did not extend to foreign soil and the latter did not apply to “unlawful enemy combatants”. Various humanitarian and legal advocacy groups claimed that these policies were unconstitutional and violated international human rights law;[5][6] several landmark U.S. Supreme Court decisions found that detainees had rights to due process and habeas corpus but were still subject to military tribunals, which remain controversial for allegedly lacking impartiality, independence, and judicial efficiency.[7][8]
https://en.m.wikipedia.org/wiki/Guantanamo_Bay_detention_camp