it is because after ww1 ended, the ww1 led the consequences of ww2. to be much clear, for example, ww1 ended with the blaming of the Germans, meaning that the Germans had to face much harder consequnces than other countries. this led the Germans to grow their hatred and to secretely build up their powers to fight back, meaning that the Germans were united under Nationalism and we can conclude that after ww1 ended, ww2 was already beginning to shape
