It was only 3 weeks ago that I found out that Japan had a nuke program during WW2 and actually tested their own device (about 1/5 the size of our 1st) in February 1945. I wasn’t actually surprised that they had a nuke program; I was surprised that they were 5 months ahead of us.
We were lucky that they used up all their materials in their test and couldn’t immediately make a second device to use against us.
The Jap Nuke program was centered in Korea. The Russians stole everything after the war.