Brett’s Question: As a follow-up to the Italy question- what was the relationship like between Japan and Germany? I now understand Japan’s motives, but was the relationship just a loose connection based on a common enemy?
Japan and Germany are on opposite ends of the Earth and therefore their geopolitical interests don’t often coincide or conflict. It’s hard to believe they would become allies except for this other blatant geopolitical fact: Japan and Germany are on opposite ends of the USSR!
In East Asia, Japan, China, and USSR all had economic interests in Manchuria which was resource rich. Japan being a mountainous island nation needed more land and resources, much like Germany needed resources. If Germany invades the USSR from the west, then Japan would invade the eastern half of the USSR. Divide the USSR and conquer the world.
Second, both the Japanese and the Germans were avowed anti-Communists. While you might not consider the Japanese as traditional fascists like Germany and Italy, they were also militaristic and thus akin in certain ideals. The Japanese are also racist in the sense that they considered themselves superior to all the other Asian groups, especially the Chinese and Koreans. Birds of the same feather flock together.
Before World War 1, German colonial interests in the Far East were small compared to France and the UK – just one city in northern China and a few small islands. And after WW1, the Germans under the Weimar Republic and later Nazi Germany had no interest in regaining them. They seemed content to let Japan extend its influence and power to form the Greater East Asia Co-Prosperity Sphere.
There is also proof that the Japanese and Germans shared technology. At least the Germans did; there is confirmed proof that the Germans shipped some stuff to the Japanese by U-boat.
Thus, the Japanese and Germans have the Russians as their common enemy and both stood to gain when they act in concert. Whether both sides combined could have won the war and divided the world between them is doubtful and whether they would have tolerated each other is also doubtful. That’s for science fiction and alternate historians to argue over (Watch The Man in the High Castle series).