"Even though all of the lengthy, extensive and illegal torture he was subjected to happened while he was a guest of Uncle Sam, the Canadian government was partly complicit in those abuses; he was at one point subjected to days of sleep deprivation in order to soften him up for an interrogation by Canadian officials. The Supreme Court said as much."
***
I prefer the definition of torture from the Oxford Dictionary of Current English:
"infliction of severe bodily pain esp. as punishment or means of persuasion; severe physical or metal pain."  

Note the terms, "severe" and "pain".