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.”
We did not have to nuke the Nazis. We had to nuke Japan.
They took on Russia at one point (early 1900s) and won. They beat the #### out of China several times.
In fact, just about the only nation to ever beat them is the U.S.
Messing with them is a BAD idea.
/Not saying their actions were moral or justified, just stating facts.