fairly common knowlege that Germany & Japan were working on nuke bombs but I don't recall ever hearing that they got close to having one that worked
In the book : The German Atom Bomb : it was found after the war that the german atomic program never got further than a university project, uranium cubes hung on strings in a bavarian cave. Hitler didn't like the U235 fission bomb idea because it had been developed in part by JEWS; plus Heisenberg steered nuc-development toward power generation, not bombs. All he could think of, as a bomb, was to fly the entire 1/2 a million pound reactor w/control rods in a plane and drop it over london, pulling all the control rods at once. Nazi Germany never developed an airplane capable of lifting 500,000 # of course... But as to a rogue sub commander trying to start WWIII it just might have been possible. Do you remember that in the Cuban Missile Crisis the local russian commanders had total control of their own nucs? Thus if Kennedy HAD ordered air strikes on the cuban nuc bases, say in retaliation for the shooting down of the US spy plane, IT could have happened right then and there as the USSR missiles already in cuba had a 1000 mile range. Thus one could argue the case for a rogue sub commander in the 1960's and someone else on the sub, knowing what this all meant, could have sabotaged the sub to prevent WWIII. What was the name of that russian spy that fed the british and US intelligence guys the actual facts on the USSR's nuclear forces and capabilities? With that info Kennedy called Khruschev's bluff. Might not there have been a similar russian patriot on the K-129 sub? Maybe one could make a might-have-been sub movie out of that...a noble man who saw thru the communist LIES and sacrificed himself for ALL of us...an un-sung hero of the cold war...plot then : deep submersible hunting thru the 2/3rds of K-129 still down there, trying to find(as undersea detectives)who, where and how it was sabotaged...
What this special, which I saw twice, stated was that Germany had the fissionable materials that Japan lacked. Japan had gotten as far as they could with the technology and a German sub was on it's way to Japan with that material when Germany surrendered. They radioed the sub but the sub commander thought it was a trick and kept on going. I don't remember how the event was finally resolved but the material did not fall into Japanese hands. I'll have to look on the History Channel's website. I think that all the episodes they run can be purchased on video or DVD.