Just before WWI, europe was very unstable, germany make an alliance with austria and with italy (the triple-alliance), while another alliance was formed; the france-england-russia alliance. The archduc Ferdinand and his wife Sophia were killed by a Bosniac, then Austria decide it was enough, they want to give a lesson to these serb, so they ask Germany if they could count on them, and Germany answer Yes, Austria could count on Germany if there was a war. Then (to make the story short) Austria declared war against the Serb, the Serb had ask before help from Russia, they accept to help the Serb but ask France, France accept to help Russia in case of a war, then Russia accept to help the Serb. Then the war start between the Serb and Austria, and shorty after that, between Russia-France and Austria-Germany. The war was horrible, ~20 000 000 death, but if we look at it, germany was not the “monsters” in it, sure they use gas bur France and England take people from their colonies to throw them in the frontline…
Anyway, after the War, Germany was humiliated, his economy was shattered. Then right-wing extremist use the fear and desolation of the german people to their advantage, the Germans dissident were killed, and lots of german were anyway not so dissident…
THIS, is a context. In no way an excuses for Nazi’s atrocities.
Same thing goes, on a lesser scale, for the us nuclear attack. You are trying to rationalize horribles crimes, but throwing two nuclear bomb on civilian was a terror attack. Remember that without the “unconditional reddition”, the two bomb would have maybe not been necessary. Sure we own a lot to Russia and the US, it is not a reason to be blind to their crime, i am happy the USA help to get the war to and end, but Nagasaki and Hiroshima were more political/emotional than rational desicion.