Howard Zinn said this quote
“ The argument that there are just wars often rests on the social system of the nation engaging in war. It is supposed that if a ‘liberal’ state is at war with a ‘totalitarian’ state, then the war is justified. The beneficent nature of a government was assumed to give rightness to the wars it wages. ...Woodrow Wilson and Franklin Roosevelt were liberals, which gave credence to their words exalting the two world wars, just as the liberalism of Truman made going into Korea more acceptable and the idealism of Kennedy’s New Frontier and Johnson’s Great Society gave an early glow of righteousness to the war in Vietnam. What the experience of Athens suggests is that a nation may be relatively liberal at home and yet totally ruthless abroad. Indeed, it may more easily enlist its population in cruelty to others by pointing to the advantages at home. An entire nation is made into mercenaries, being paid with a bit of democracy at home for participating in the destruction of life abroad. ”