There was a really good post somewhere on Reddit a while back that I can't seem to find now that had a lot more details on the idea of a Nazi atom bomb, mostly political. I think the gist was that one of the key steps in a nuclear program at the WWII stage is the realization that an artificial nuclear explosion is practical, if difficult, and makes a very effective weapon of war. That also means that they understand the core physics concepts and have some idea of what building a bomb would involve.<p>As I understand it, the Nazi regime never got to the point of even realizing that a bomb was a serious possibility. So naturally, they never devoted real resources to figuring out the details and how to go about actually building one.<p>There's also the economic aspect - the initial development work was massively expensive, and even the other major WWII combatants who had an idea that a bomb was possible didn't think they would be able to devote enough resources to it to actually build one for that war. They may well have been right - even with the massive resources the US poured into the project, the war was still pretty close to being over before they had a bomb ready to drop.
Richard Rhodes' "The Making Of The Atomic Bomb" is a pretty thorough account of the whole enterprise, and concludes that the Germans were nowhere near, so I don't think this is a particularly controversial revelation.
The U.S. had the best in uranium before the war started in a warehouse in New York:<p><a href="https://en.wikipedia.org/wiki/Shinkolobwe" rel="nofollow">https://en.wikipedia.org/wiki/Shinkolobwe</a><p>Nobody else had the raw materials in such a useful form. I say this is the quirk of history that gets overlooked when it comes to the race to get the bomb.
It turns out, driving out all of your physicists and mathematicians because they were Jewish and gutting your academic system wasn't quite the smartest idea in the world.
I have visited the Atomkeller Museum, in Haigerloch. As far as I can remember what you can see on the picture [1] from the article is almost everything there is to see. At the entrance is a glass box with a slowly ticking Geiger counter but that's it. Basically it's a small rock cavern with a hole in the ground.<p>[1] <a href="http://cen.acs.org/content/cen/articles/93/i39/Nuclear-Forensics-Shows-Nazis-Nowhere/_jcr_content/articlebody/subpar/articlemedia_0.img.jpg/1443211062695.jpg" rel="nofollow">http://cen.acs.org/content/cen/articles/93/i39/Nuclear-Foren...</a>
There's a book about Germany working on the atomic bomb from about 10 years ago. One thing that I always stuck in my mind was that the Nazis had several different programmes, run by different organizations. I remember at least three, Wehrmacht, SS, and Post Ministry (I know, this is kind of WTF). All of these organizations actively competed against each other over a very limited amount of resources, in particular heavy water and fissible material. Of course that won't produce meaningful results if you're being sabotaged by other organizations in your country.
Related to Axis bomb programs, an interesting article on Japan's: <a href="https://sites.google.com/site/naziabomb/home/japan-s-a-bomb-project" rel="nofollow">https://sites.google.com/site/naziabomb/home/japan-s-a-bomb-...</a>
An interesting quirk of history, it was the reconstituted German rocket program in the U.S. which finally gave global delivery capability to American nukes.
I was under the impression that Heisenberg made a fundamental mistake on a back of envelope calculation of the amount of an important input required that led him to believe it was not a tenable option and therefore the project was eventually killed. that doesn't mean that we didn't just get very lucky and that he might have on the flipside gotten very close to building something