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. There's actually a good discussion of it at Hot Air, which reproduces the legal definition thus:
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.
Just ask yourself: reading this language and knowing that president Bush ordered the waterboarding of a man for 83 times to get evidence linking Saddam Hussein to al Qaeda, is it really a matter of debate whether the last president of the United States is a war criminal? How is one able to come to any other opinion?
Remember:
"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"
is torture. Remember:
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.
Why are we still debating this?