Of course the means are part of a moral judgment. I meant that "justifies" is in the mind of the perpetrator. To Michael, the end (trapping Geary) justified the means (killing a hooker and pinning it on Geary). To Truman, the end (swiftly ending a war and avoiding an invasion that could have lasted three years and cost millions of casualties on both sides) justified the means (wiping out two good-sized cities instantly with nuclear weapons).

BTW: "Downfall" by Richard Frank (Random House, 1999), considered by many historians to be the definitive, detailed account of the end of the war in the Pacific, shows clearly that the Japanese were not ready to surrender, even after the Hiroshima bomb was dropped.