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.
I doubt that anyone thinks that Japan wants to attacks Russia or China.
They will have a tough enough time protecting themselves from China, and I do like that Japan spoke out against this Russian invasion.