Were there any legitimate attempts by Axis powers to disrupt the Manhattan Project?

by homeland

Not an expert by any means but I feel like the Allied attempts to throw Germany's atomic program into disarray are at the least well documented. Were there any significant attempts by Germany or its allies to slow or stop the Manhattan Project's progress?

As a corollary, I've heard bits and pieces about the Soviet's infiltration of the project - what was the ultimate goal? Information? Surveillance? Did the Soviets ever consider hampering the Manhattan Project's mission?

restricteddata

The Axis, from what we can tell, had no knowledge of the project. I've gone over what little evidence there is about German awareness of the Manhattan Project, but it is pretty much nil. The German scientists seem to have believed they were on the forefront of fission research. The Japanese, from what little we know, appear to have thought that the prospect of an atomic bomb (which they were aware of) was something beyond the capability of even the United States, within the requirements of the war.

There were some very half-hearted attempted by the Germans to have their spies (who got nabbed instantly) to poke around in nuclear matters, but even these indicated a deep ignorance: the questions the spies were meant to be looking into were not related to a bomb-making program but a reactor-developing program.

There was only one actual case of Axis disruption and it was accidental: one of the many, mostly futile "balloon bombs" launched by the Japanese against the US west coast happened to fall upon power lines that supplied electricity to the Hanford plant, which was producing plutonium for the bombs. The power disruption caused them to briefly shut down the reactor, but they were up again very rapidly. The Japanese could not have effected this outcome deliberately even if they had tried — it was just random luck.

As for the Soviets, they had many "moles" in the project. They were interested in getting information about the work done, not hampering it. Almost all of the moles were just Allied scientists who felt that the US ought not be the only nuclear superpower in the world. They were not interested in hampering the bomb development.

There were a few cases of potential sabotage at Hanford and Oak Ridge, things that slowed down work a little bit. I don't think any of them were confirmed to be sabotage (as opposed to just mistakes), but the culprit there would not have been a foreign power (or sympathy with one), but issues regarding labor management (there were fairly severe labor issues during the project).