Torture has been carried out or sanctioned by individuals, groups, and states throughout history from ancient times to modern day, and forms of torture can vary greatly in duration from only a few minutes to several days or longer. Reasons for torture can include punishment, revenge, political re-education, deterrence, coercion of the victim or a third party, interrogation to extract information or a confession irrespective of whether it is false, or simply the sadistic gratification of those carrying out or observing the torture. Alternatively, some forms of torture are designed to inflict psychological pain or leave as little physical injury or evidence as possible while achieving the same psychological devastation. The torturer may or may not kill or injure the victim, but torture may result in a deliberate death and serves as a form of capital punishment. Depending on the aim, even a form of torture that is intentionally fatal may be prolonged to allow the victim to suffer as long as possible (such as half-hanging). In other cases, the torturer may be indifferent to the condition of the victim.
Although torture is sanctioned by some states, it is prohibited under international law and the domestic laws of most countries. Although widely illegal and reviled there is an ongoing debate as to what exactly is and is not legally defined as torture. It is a serious violation of human rights, and is declared to be unacceptable (but not illegal) by Article 5 of the UN Universal Declaration of Human Rights. Signatories of the Geneva Conventions of 1949 and the Additional Protocols I and II of 8 June 1977 officially agree not to torture captured persons in armed conflicts, whether international or internal. Torture is also prohibited for the signatories of the United Nations Convention Against Torture, which has been ratified by 158 countries.
National and international legal prohibitions on torture derive from a consensus that torture and similar ill-treatment are immoral, as well as impractical, and information obtained by torture is far less reliable than that obtained by other techniques. Despite these findings and international conventions, organizations that monitor abuses of human rights (e.g., Amnesty International, the International Rehabilitation Council for Torture Victims, Freedom from Torture, etc.) report widespread use condoned by states in many regions of the world. Amnesty International estimates that at least 81 world governments currently practice torture, some of them openly.
The United Nations Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, which is currently in force since 26 June 1987, provides a broad definition of torture. Article 1.1 of the UN Convention Against Torture reads:
For the purpose of this Convention, the term "torture" means any act by which severe pain or suffering, whether physical or mental, is intentionally inflicted on a person for such purposes as obtaining from him, or a third person, information or a confession, punishing him for an act he or a third person has committed or is suspected of having committed, or intimidating or coercing him or a third person, or for any reason based on discrimination of any kind, when such pain or suffering is inflicted by or at the instigation of or with the consent or acquiescence of a public official or other person acting in an official capacity. It does not include pain or suffering arising only from, inherent in, or incidental to, lawful sanctions.
This definition was restricted to apply only to nations and to government-sponsored torture and clearly limits the torture to that perpetrated, directly or indirectly, by those acting in an official capacity, such as government personnel, law enforcement personnel, medical personnel, military personnel, or politicians. It appears to exclude:
An even broader definition was used in the 1975 Declaration of Tokyo regarding the participation of medical professionals in acts of torture: