[StormPrepper]

In 1946 it was reported in news papers that Japan had actually tested an atomic bomb. There was also a witness.

Germany tried to make something from heavy water, which was nothing. Although Germany did have Uranium and tried to send 1000lbs of it to Japan.

[colorado tanker]

Japan dropped its program, concluding it did not have the vast resources necessary to build a fission bomb. They didn't think we did, either.

When the second bomb dropped, they discovered not only did we have the resources, but we had enough to build the bombs two ways, uranium and plutonium. It was shock and awe to the Japanese scientists and engineers who understood what we had done.

[Karl Spooner]

The top German scientists purposely led the atomic program to heavy water knowing it would be unfruitful.

[chimera]

The heavy water was for their test reactor. Heisenberg didn't think there would ever be graphite pure enough to build a reactor using graphite and natural uranium. He knew heavy water would work, so he went down that path. Fermi proved him wrong by getting the purity of graphite to the point where criticality using natural uranium could be attained. Various commando raids (some successful, others disastrous) were launched to interdict the heavy water shipments from Norway to Germany.

[LS]

It may have been reported, but Japan was nowhere close to making a bomb. Germany was somewhat closer, but abandoned the program in 1942, when Hitler decided to throw all his resources at the USSR. However, our intelligence still thought a German bomb (but never a Japanese bomb) was a likelihood and had assassination teams out as late as 1944 to kill Werner Heisenberg.