In this volume the decisive battles were on the Russian front. At Stalingrad the Germans were held and forced to retreat. At Kursk the Soviets nullified the advantage that the Germans previously had in tanks and aircraft and again the Germans were forced to retreat. On the Atlantic Ocean the Allies gained superiority through the use of intelligence and aircraft. In North Africa the Germans were defeated and the battle was resumed in Sicily. In the Far East the Japanese still controlled most of the Pacific Ocean, but the Americans were building ships to confront them. In the South Pacific the war continued at Guadalcanal which was in part a land battle and in part a sea battle. The British lost Malaya and the fight continued in Burma with Japan having the upper hand. All these battles on several fronts were nothing compared to the production of the atom bomb. Oppenheimer was the brains behind the bomb, but its production was a great engineering feat which has been underrated. The man who organised this was General Leslie Groves. This massive endeavour, which in the context of the war could only be done by the US. Nils Bohr did not believe they could do it and he was nearly right. It was the brilliance of the nuclear scientists that created the bomb but it was the engineers that delivered it.

To do this task required enormous competence. Groves wanted a field command but was prevailed upon to lead the Manhattan Project. Groves could be abrasive and appear to others to be over confident but the biggest compliment he was paid was that he produced the best out of people revealing their intrinsic abilities. For an engineer to do this to the world's greatest scientists was a major achievement. He believed in the competence and brilliance of Oppenheimer and was not phased by his communist connections. The one scientist with whom he had difficulties was Leo Szilard, an able man, but to Groves he was disruptive and not a team player. Szilard was contemptuous of an engineer making decisions on a par with the intellectual brilliance of the scientists. Yet the Manhattan Project was an engineering project and Groves delivered. It was a tour de force with a team that worked together at the highest creative level.