Define torture
Excellent suggestion!
Merriam-Webster:
The infliction of intense pain (as from burning, crushing, or wounding) to punish, coerce, or afford sadistic pleasure.
Interesting that torture can be considered pleasurable....
Intense tickling can also be considered torture, if the recipient is unwilling to participate (i.e., a child).
Expand your definition of torture, which includes "sadistic" and you get:
sad·ism (sā′diz′əm, sad′iz′əm)
1.the getting of sexual pleasure from dominating, mistreating, or hurting one's partner
2.the getting of pleasure from inflicting physical or psychological pain on another or others
If the US had previously prosecuted folks for war crimes for the torture excessive tickling, you'd have a point.