In that situation, would anybody have gotten around to inventing the atomic bomb? Who? When? (Something to consider is the question of whether, in this world, nuclear weapons were ever truly reinvented?)
Now, imagine another scenario in which it's 2010, but nuclear technology has remained at rudimentary 1930s levels ever since the 1930s. Everything else is the same about the world of 2010 — They've got computers, lasers, titanium, Powerpoint, Twitter, whatever — just that nobody ever got around to working on nukes.Â
Then, some country in this Alternative Present decides to build an atomic bomb. With all the 21st Century advantages, would they do it faster than the Manhattan Project? Would they even set one off by 2020?