Richard A. Posner The European rejection of the death penalty, which advocates of abolishing the death penalty in the United States cite as evidence of an emerging international consensus that ought to influence our Supreme Court, is related both to the past overuse of it by European nations (think of the executions for petty larceny in eighteenth-century England, the Reign of Terror in France, and the rampant employment of the death penalty by Nazi Germany and the Soviet Union) and to the less democratic cast of European politics, which makes elite opinion more likely to override public opinion there than in the United States.

(Richard A. Posner, How Judges Think [Cambridge and London: Harvard University Press, 2008], 351)

Note from KBJ: We Americans kill murderers because we value innocent human life. That is one of many ways in which the United States is morally exceptional.