WI: No Soviet infiltration of the Manhattan Project?

[MorphyVSFischer]

Or at least minimal enough that the don't get any valuable information from them. How much would there own project be delayed by this?

 

[Theoretical_TJ]

I'd say at least as much as the British Blue Danube program. The entire German program showed how much a faulty approach would essentially never yield a weapon. Add to that the fact the British helped develop it and had some of the base knowledge to get started.

 

[David T]

See David Holloway, *Stalin and the Bomb: The Soviet Union and Atomic Energy 1939-1956* (Yale University Press 1994). He acknowledges the important role played by espionage, but adds (p. 366):

"The best estimates suggest, however, that the Soviet Union could have built a bomb by 1951 or 1952 even without intelligence about the American bomb. There already existed in the Soviet Union strong schools of physics and radiochemistry, as well as competent engineers. Soviet nuclear research in 1939-41 had gone a long way toward establishing the conditions for an explosive chain reaction. It was because Soviet nuclear scientists were so advanced that they were able to make good use of the information they received from Britain and the United States about the atomic bomb. Soviet scientists showed their ability by developing thermonuclear weapons independently. Although the Soviet Union did receive information about American research on thermonuclear weapons, this information was misleading rather than helpful. The nuclear project was a considerable achievement for Soviet science and engineering." https://books.google.com/books?id=ICO6aUnQ2KcC&pg=PA366

 

[sloreck]

If Stalin does not get his first device until 1951-52 this makes a huge difference. Don't forget that it was a device not a deployable weapon. I can't see Stalin giving the OK to Kim the first to cross the border if the USA still has an atomic monopoly. As long as the USA has the monopoly Stalin's threat to Europe/NATO is much diminished. Also absent a Soviet bomb IF the war goes off when it did I expect Truman will be amenable to unifying Korea. Would the Chinese intervene as they did - hard to know, while Mao was not "afraid" of the bomb would he push forward without assurance of Soviet technical support, pilots, materiel, etc. Without a Soviet bomb Truman might very well be willing to have conventional attacks on the Chinese side of the Yalu.

Of course, without the Soviet atomic test, the modernization of the US arsenal will probably not proceed as rapidly as OTL - US atomic capabilities in 1948 were actually pretty poor, and making better and more useful weapons was accelerated with the Soviet test. In 1951-52 the US will be better off than in 1948, but will they be as advanced as OTL? Also, without an immediate Soviet threat will the shift to relying on an atomic force be as advanced as OTL. Will the supercarriers be cancelled as OTL? Will the army be as ignored as OTL?

Lots of butterflies busy flapping here.