Nuclear Weapons Programs programs of the Western Allies As in many other areas of major technical effort by the Soviet command economy, atomic research was advanced through primary reliance on coercion, terror, and forced labor That included hundreds of thousands of slaves and prisoners exposed to natural radiation while working Soviet uranium mines, and thousands killed in industrial accidents or by gross and malign neglect The Soviet program was also held back during the war by the fact that a number of top scientists died in the prewar Yezhovshchina Based on ULTRA intercepts and other espionage, by 1943 the British—and in late 1944 also the Americans—came to the conclusion that Germany had curtailed its nuclear weapons program and was essentially out of the “atomic race.” Also in late 1944, top Western leaders were advised that the first workable bombs might be ready by the late spring of 1945 Within a few months it was clear that German resistance would not last into the summer Planning therefore began to focus on Japan, where it was thought hard and bloody resistance would continue for at least 18 months after the end of the war in Europe One of the curious facts about Western Allied counsel on whether or not to use the bombs is that President Franklin Roosevelt always and quite vehemently opposed first use of gas or nerve weapons, but expressed no qualms about the atomic bomb That fact confirms that he, like most policy makers, thought of atomic weapons as super bombs to better what they were already doing—destroying cities from the air—and not as a new kind of terror weapon It may also reflect the fact that the world had seen the horrors of gas during the Great War, but had yet to experience atomic attacks President Harry Truman seems to have made the same core assumption The key idea about use was the same rationale behind morale bombing, though with much greater punch: to create psychological shock in Japan sufficient to end the war Prime Minister Winston Churchill later recorded his thoughts: “to bring the war to an end, to give peace to the world, to lay healing hands upon its tortured peoples by a manifestation of overwhelming power at the cost of a few explosions, seemed after all our toils and perils, a miracle of deliverance.” The Manhattan Project team tested the first ever atomic bomb in the western desert of the United States: the first “Trinity” test of the “Gadget” was made at Alamogordo, New Mexico, at 5:29:45 A.M on July 16, 1945 That was six weeks after the unconditional surrender of Nazi Germany, against which the race to build the bomb was initially run Stalin was informed about the weapon by Truman on July 25, during the Potsdam conference Stalin already knew about the success of the Manhattan Project from well-placed spies inside it, notably Klaus Fuchs and Julius Rosenberg The first two operational bombs—code-named “Little Boy” and “Fatman”—were dropped from B-29s, destroying much of central Hiroshima and Nagasaki, respectively “Little Boy” was a uranium bomb “Fatman” was a more powerful plutonium bomb, the same design as the “Gadget” bomb tested in New Mexico Both were fission bombs that produced extraordinary destruction of lives and property primarily from blast and heat effects Short-term or “prompt” radiation and fallout were anticipated, though not as much as was actually produced After the war, one scientist put the operating assumption about radiation this way: “any person with radiation damage would have been killed with a brick first.” 800