Britain was bankrupt after ww2 and focused on domestic issues and the giving up of empire. France was even more dire and reconstructing. But, whilst Russia wa

Britain was bankrupt after ww2 and focused on domestic issues and the giving up of empire. France was even more dire and reconstructing. But, whilst Russia was shattered, it diverted far bigger resources to gaining some sense of parity with the US after the war than other countries. The USSR looked to the west as a threat; the Brits and the French didn't fear their ally the US, and didn't need to get a bomb of their own with such urgency (until the USSR got the bomb, that is. Suddenly also having the bomb was strategically important.)