Waterboarding is legal because White House says so. Waterboarding is not torture because it can be legally justified.

Torture, according to the UN Convention Against Torture is:

"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."

I'm not a lawyer but surely waterboarding falls under this definition. How can it be legal at times and illegal at other times? Torture is torture no matter how, when, or why it is performed.