Earlier quoted context omitted.
Yes, the Allies comitted war crimes in WWII, i don't see how that matters for modern war criminals. Conspiracy against peace is a real war crime, including in the US.
I guess you and I must disagree. Either you think war crimes are no big deal, because according to your broad reading of "conspiracy against peace" pretty much anyone who participates in any war is a criminal, or else you think there is no justifiable war whatsoever. Personally I think WWII was entirely justified, that the Allies had to win that war, and that fighting to win meant that large numbers of people would d…
> crime against peace, in international law, is "planning, preparation, initiation, or waging of wars of aggression, or a war in violation of international treaties, agreements or assurances, or participation in a common plan or conspiracy for the accomplishment of any of the foregoing".[1] This definition of crimes against peace was first incorporated into the Nuremberg Principles and later included in the United Nations Charter. This definition would play a part in defining aggression as a crime against peace. It can also refer to the core international crimes set out in Rome Statute of the International Criminal Court (genocide, crimes against humanity, war crimes, and the crime of aggression), which adopted crimes negotiated previously in the Draft code of crimes against the peace and security of mankind.
> An important exception to the foregoing are defensive military actions taken under Article 51 of the UN Charter. Such defensive actions are subject to immediate Security Council review, but do not require UN permission to be legal within international law. "Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations." (UN Charter, Article 51) The Security Council will determine if the action is legally the "right of individual or collective self-defence", or it may appoint another UN organ to do this.
Meaning that defensive wars are OK. Conspiring against the peace, aka waging a war of aggression, is not. Which is why the Allies fighting against the Axis aren't war criminals for being in the war, but for their actions there ( unrestricted submarine warfare, the Laconia incident, the bombings of civilian targets including Nuremberg, etc.). The Axis' war crimes including them starting the wars ( against Poland, Soviet Union, Greece, Yugoslavia, etc.) and their despicable behaviour in them ( Holocaust, treatment of civilians and POWs, bombing of civilian targets, etc).