The Soviets were going to do it in a few years anyway. Maybe it would not be as quickly as they got it done. Japan even had a wisp of a program. Everybody knew that an atom bomb program was a thing to do.

At the barest minimum, we would still develop nuclear reactors, and then plutonium would get discovered, and it’s easy to manufacture and purify (compared to U-235), and the bomb is just a matter of time.