After World War II we tried, convicted, and executed Japanese solders for waterboarding prisoners. We executed the people performing the waterboarding. We executed the people who ordered the waterboarding.
and quoting from elsewhere on the web:
The UN Convention on Torture, which Ronald Reagan signed and championed, is very clear and its definition of what torture is obviously broad and inclusive.
Article 1.
1. For the purposes of this Convention, 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.
2. This article is without prejudice to any international instrument or national legislation which does or may contain provisions of wider application.
Article 2.
1. Each State Party shall take effective legislative, administrative, judicial or other measures to prevent acts of torture in any territory under its jurisdiction.
2. No exceptional circumstances whatsoever, whether a state of war or a threat or war, internal political instability or any other public emergency, may be invoked as a justification of torture.
3. An order from a superior officer or a public authority may not be invoked as a justification of torture.
