In WW1, the Japanese army only had to clean up what it could get from the German colonial possessions. Tsingtao was its biggest engagement and went well. It had not cost the lives of countless Japanese soldiers.
Contrast that to WW2, where you have an army that has been fighting in China since 1931 and then was thrust into the jungles of southeast Asia and the Pacific in a bitter fight for survival against the British and Americans. When you have spilled your blood, you are less predisposed to the gallantries of "civilized" fighting.
<span>And then you have the precedent of these exact same foes having turned down Japan's </span>Racial Equality Proposal<span> in 1920. The Japanese understood that the westerners were still looking at them as inferior. That resentment had time to fester in the intervening 20 years, among the ranks of the Japanese army officers.</span>
<span>Last but not least, in the interwar years the entire world saw a slide to totalitarianism, with Japan being no exception
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c. The government banned slave labor and racial discrimination.
Idk. .......................
