Let me ask you this, which -assuming that you consider either to be wrong- was worse: Pinochet detaining and killing some 2,000 people in an internal war to stop communist incursion; or the United States using the atomic bomb to incinerate over 100,000 people in a city virtually devoid of any targets of military necessity in order to stop the imperial japenese?
Personally, I think the U.S. should have dropped the bomb on a military target (or in Tokyo Bay- that should catch the imperialists' attentions), but I also consider the U.S. to have saved the lives of the JAPANESE with the nuke by not forcing the war to a halt, thus causing no more civilians to starve to death or soldiers to die in combat.
Pinochet, on the other hand, practiced military dictatorship and terror through the state.
So I'll go with Pinochet being worse, obviously, since the use of a-bombs in WWII was the correct thing to do. Though I'd quibble with the details, but that's another matter.