Was Hitler intelligent? Of average intelligence like most of us I think. But the question should be ?was he clever?? in relation to the atomic bomb project he initiated. I think not: The German project had fundamental flaws from its conception. Many top German scientists had left Germany, some of them Jewish ?migr?s fleeing the new laws of German National Socialism. Other scientists left in protest, significantly decreasing the number of experts available to work on a German bomb. A substantial number eventually came to the United States to work on the Manhattan Project. It was Otto Hahn and Lise Meitner who discovered fission, well, Meitner actually though Hahn did his best to take the credit. She was from Jewish extract but became a protestant but had to flee to Stockholm and Hahn began to erase her from the history of fission, even having her name removed from the lab they shared but still had to correspond with her to help him understand fission. Heisenberg claimed after the war he had sabotaged the German project but in reality he got the mean free path of neutrons required for a chain reaction wrong, calculating one ton of enriched uranium would be required in fact it was one Kg. From July 3, 1945, to January 3, 1946, the Allies incarcerated ten German nuclear physicists a the English country estate of Farm Hall, their goal being to obtain information about the German nuclear research project by way of surreptitiously taped conversations. They were shocked when they heard about the atomic bombs dropped by America having made such a fundamental flaw in their calculations. So if Hitler didn?t have such a hatred for Jews and had imprisoned the top Jewish scientists from Germany and Eastern Europe who fled to America and worked on the Manhattan Project we may have had a different out come. Fortunately he was more impressed by Von Braun and his rockets. https://www.sdsc.edu/ScienceWomen/meitner.html