Perhaps the most notable international agreement prohibiting the use of torture is the United Nations Convention against Torture and Other Cruel, Inhuman, or Degrading Treatment or Punishment (Convention or CAT), which obligates parties to prohibit the use of torture and to require the punishment or extradition of torturers found within their territorial jurisdiction. CAT Article 3 requires that no state party expel, return, or extradite a person to another country where "there are substantial grounds for believing that he would be in danger of being subjected to torture." Implementation of the Convention Against Torture in the United States

The United States signed CAT on April 18, 1988, and ratified the Convention on October 21, 1994, subject to certain declarations, reservations, and understandings, including a declaration that CAT Articles 1 through 16 were not self-executing, and therefore required domestic implementing legislation. This section will discuss relevant declarations, reservations, and understandings made by the United States to CAT, and U.S. laws and regulations implementing the Convention. With respect to the provisions of CAT Article 3 prohibiting expulsion or refoulement of persons to states where substantial grounds exist for believing the person would be subjected to torture, the United States declared its understanding that this requirement refers to situations where it would be "more likely than not" that an alien would be tortured, a standard commonly used by the United States in determining whether to withhold removal of an alien for fear of persecution. Foreign Affairs Reform and Restructuring Act of 1998

The Foreign Affairs Reform and Restructuring Act of 1998 (FARRA) announced the policy of the United States not to expel, extradite, or otherwise effect the involuntary removal of any person to a country where there are substantial grounds for believing that the person would be in danger of being subjected to torture. Regulations Concerning the Removal of Aliens

The requirements of CAT Article 3 take the form of a two-track system requiring the withholding or deferral of an alien's removal to a proposed receiving state if it is more likely than not that he would be tortured there. Summary Exclusion of Arriving Aliens Inadmissible on Security and Related Grounds 61

U.S. law designates certain arriving aliens as inadmissible on security-related grounds, including for having engaged in terrorist activities. In Zadvydas v. Davis , the Supreme Court concluded that the indefinite detention of deportable aliens (e.g., aliens who were admitted into the U.S., and thereafter committed an immigration violation that caused them to become removable) would raise significant due process concerns. It is important to note that CAT only prohibits signatory parties from expelling persons to states where they would likely to be tortured—it does not provide aliens with protection from removal to states where they would not be tortured, even if such aliens would face cruel, inhuman, or degrading treatment not rising to the level of torture. For a detailed discussion concerning the legality of renditions under the laws on torture, including CAT, see CRS Report RL32890, Renditions: Constraints Imposed by Laws on Torture , by [author name scrubbed].
The United Nations Convention Against Torture and Other Cruel, Inhuman, or Degrading Treatment or Punishment (CAT) requires signatory parties to take measures to end torture within their territorial jurisdictions. For purposes of the Convention, torture is defined as an extreme form of cruel and inhuman punishment committed under the color of law. The Convention allows for no circumstances or emergencies where torture could be permitted. Additionally, CAT Article 3 requires that no state party expel, return, or extradite a person to another country where there are substantial grounds to believe he would be subjected to torture. CAT Article 3 does not expressly prohibit persons from being removed to countries where they would face cruel, inhuman, or degrading treatment not rising to the level of torture.
The United States ratified CAT subject to certain declarations, reservations, and understandings, including that the Convention was not self-executing, and therefore required domestic implementing legislation to take effect. In accordance with CAT Article 3, the United States enacted statutes and regulations to prohibit the transfer of aliens to countries where they would be tortured, including the Foreign Affairs Reform and Restructuring Act of 1998, and certain regulations implemented and enforced by the Department of Homeland Security (DHS), the Department of Justice (DOJ), and the Department of State. These authorities, which require the withholding or deferral of the removal of an alien to a country where he is more likely than not to be tortured, generally provide aliens already residing within the United States a greater degree of protection than aliens arriving to the United States who are deemed inadmissible on security- or terrorism-related grounds. Further, in deciding whether or not to remove an alien to a particular country, these rules permit the consideration of diplomatic assurances that an alien will not be tortured there. Nevertheless, under U.S. law, the removal or extradition of all aliens from the United States must be consistent with U.S. obligations under CAT.
CAT obligations concerning alien removal have additional implications in cases of criminal and other deportable aliens. The Supreme Court's ruling in Zadvydas v. Davis suggests that certain aliens receiving protection under CAT cannot be indefinitely detained, raising the possibility that certain otherwise-deportable aliens could be released into the United States if CAT protections make their removal impossible. CAT obligations also have implications for the practice of "extraordinary renditions," by which the U.S. purportedly has transferred aliens suspected of terrorist activity to countries that possibly employ torture as a means of interrogation. For additional background on renditions and other CAT-related issues, see CRS Report RL32890, Renditions: Constraints Imposed by Laws on Torture, and CRS Report RL32438, U.N. Convention Against Torture (CAT): Overview and Application to Interrogation Techniques, both by [author name scrubbed].