The Japanese badly defeated Russia in 1905.
“The Russo-Japanese War of 1904-05 was fought between the Empire of Russia, an international power with one of the largest armies in the world, and the Empire of Japan, a nation which had only recently industrialized after two-and-a-half centuries of isolation.”
This isn’t the Japan of 1905 anymore. They wouldn’t bother actually invading Asia at all nowadays given that it would not be hard for China or Russia to nuke them with weapons that make the bombs used on Hiroshima and Nagaski look like party poppers in comparison. Hundreds of kilotons or multiple megatons is what China or Russia has ready to use as nuclear weapons. What we used on Japan was way smaller at only 15-20 kilotons.