Why didn't Japan fight with Germany against the Soviet Union when they were Axis powers in World War II?

The Japanese navy spent most of its resources on military spending and built many large steel warships, although these were used infrequently against the Soviet navy.

In addition, Siberia lacks the oil and rubber resources that Japan desperately needs, so it is not strategically important and can be said to be a useless resource.

It is worth mentioning that Japan has had two painful experiences, the first is after the first World War, the Japanese army involved in the Far East battlefield, encountered brutal cold weather, caused heavy losses;

The second was at the Battle of Nomenkan in 1937, when the Japanese Army lost its only panzer division, dealing a huge blow to the army's morale and leaving a psychological shadow.

In fact, the Japanese Kwantung Army tried to create friction with the Soviet Far Eastern Border guards, but was defeated.

The only armored brigade they ever had was wiped out in a battle with the Soviet Far Eastern Border guards.

Thus, Japan was already afraid of further conflict with the Soviet Union, and even when Germany advanced on Moscow, Japan did not again consider taking action against the Soviet Union.

Moreover, Japan and the Soviet Union had different strategic goals.

Japan's initial goal was to split Manchu and Mongolia, and it planned to occupy the region for a long time, so it conducted a lot of assimilation education and carried out developmental construction.

Then they developed a strategy to swallow China, and in order to achieve this goal, they attacked Southeast Asia, but were eventually defeated by the US Navy.

Therefore, Japan was always reluctant to go to war with the Soviet Union to prevent the war from spreading to its home front.

Similarly, the Soviet Union had similar considerations.

They wanted to solve the German problem in Europe first, so they were reluctant to commit troops to Siberia.

Therefore, the two sides signed a non-aggression pact to ensure the security of their respective home front.