America the Murderous

Forget about the natives, lynchings, immoral wars, homicide rates and having practically invented the serial killer.  Why is the U.S.A. the only developed western nation that still employs capital punishment?

So when a dictator murders you it's fine, but when a war America fights against your dictator results in inevitable collateral damage, which is entirely justified for the greater good of mankind, all of a sudden we're the bad guys.