Not really. Political leaders are like mosquitos - opportunistic bloodsuckers (that, BTW, holds for corporate management as well). How much they suck depends not on their own ability to suck (for they possess none), but on the blood pressure in the vessel into which they happen to tap. In other words, the amount of blood they sucked or spilled in the function of the opportunity they encounter.
The fact that swine like Truman who ordered nuking civilian targets Hiroshima and Nagasaki, not to mention fire bombing of Tokyo or carpet bombing of Dresden (intentionally directed at civilian targets) or Nixon who ordered the bombing of Cambodia -- did not have the opportunity to kill as many as Pol Pot did should not be counted as the proof of their benevolent nature.
Ah, and do not forget the genocide of the Native Americans. That they were not as numerous as European Jews should not provenet us from seeing that US presidents pioneered genocidal policies of the same sort as those later pursued by Adolf Hitler.
regards, WS