I have already stated on many occasions that the Allies did not win the Second World War. Nazi Germany (actually, its’ almighty Führer Adolf Hitler) lost it. He lost it by making a long series horrendous strategic mistakes (monumental blunders, actually) which ultimately cost him his war, his Reich and his life.
One of such blunders was his decision to ignore the Uranprojekt – the German nuclear weapons project – which was commenced in April 1939, just four months after the discovery of nuclear fission in December 1938 and three years (!) before the start of the Manhattan Project – the American nuclear weapons effort.
Without crucial support from the top, the project ended after just five months – in September 1939 when many notable physicists were… drafted into the Wehrmacht after the start of World War II.
However, even before it ended (actually, on the very first day of the Second World War), the Heereswaffenamt – the German Army Weapons Agency – commenced the alternative Uranprojekt. Which in a matter of weeks became the only nuclear weapons project in the Third Reich.
The program eventually expanded into three main efforts: the Uranmaschine (nuclear reactor), uranium and heavy water production, and uranium isotope separation.
However, four factors ultimately doomed this project and prevented the Nazis from building an atom bomb ahead of the Americans. First, the project was ignored (not opposed, just ignored) by Adolf Hitler. Which made it a low priority – too low to be successfully completed in wartime.
Second, the Uranprojekt did not have a “tsar” with dictatorial powers (for some reason, Nazis did not apply the seemingly omnipresent Führerprinciple to this project).
Although Abraham Esau – a highly talented German physicist and a co-founder of the first nuclear weapons effort – was appointed as Hermann Göring’s plenipotentiary for nuclear physics research in December 1942, he was not given sufficient executive power.
Uranprojekt was split up among nine major institutes where the directors dominated the research and set their own objectives. Which often conflicted with the ultimate objective – building an aircraft-deliverable nuclear bomb.
Third, it was (incorrectly) assessed that nuclear fission would not contribute significantly to winning the war (the reality was exactly the opposite), and in January 1942, the Heereswaffenamt turned the program over to the Reich Research Council (Reichsforschungsrat) while continuing to fund the program. Which obviously pushed the Uranprojekt further down the priority chain.
Not surprisingly, the number of scientists working on applied nuclear fission began to diminish, with many applying their talents to more pressing war-time demands. Which further depleted human capital necessary for the successful development of a nuclear weapon.
Depletion of the human capital was exacerbated by the fourth factor – the political and ideological one. Politicization of the German academia under the National Socialist regime had driven many physicists, engineers, and mathematicians out of Germany as early as 1933. Those of Jewish blood who did not leave were quickly purged from German institutions, further thinning the ranks of qualified physicists and engineers.