Korea , Nam and Iraq are but the tip of the iceberg. How about Pol Pot who opposed Communism and with US approval exterminated 3,000,000 Cambodians. Uncle Sam----Not a word. 
And what about the planets most ruthless and barbaric tyrants who have been backed, supplied and supported by the morally virtuous US of A? 
" Regime Change " ...AKA, you do as we tell you to or we'll initiate another, " Regime Change "
OH!!! LOOK!!........Some of Uncle Sam's partners in crime. 
http://www.alternet.org/world/35-countries-where-us-has-supported-fascists-druglords-and-terrorists