The Soviet Union could defeat Japanese forces on land in the late 1930s even though its Far Eastern navy could barely contest the Imperial Japanese Navy. After Tsushima, Japanese naval planners no longer treated Russia as a local peer and focused on the Royal Navy and U.S. Navy. The Imperial Japanese Army faced a different map because Russian, and later Soviet, forces remained across a vast land frontier. The two services could therefore assess the same northern opponent very differently.
Notable Point · 21:31-24:01
How Tsushima split Japanese naval and army threat perceptions
Tsushima removed Russia from the Imperial Japanese Navy's list of local peers, while the army still faced a large continental opponent.