Actually, WWII was very far from being just in the "Just War" concept. One of the basic tenets it violated was that unconditional surrender was the only stated outcome for the allies. You must be willing to negotiate terms to qualify for a just war.
I think the first Gulf War was a good example of a just war.
And just who were you to negotiate with in a TOTAL WAR situation where the Japanese fought maniacally to the death, and the Germans didn't dare broach the idea to der Fuhrer on pain of instant firing squad.