Could Britain have completed Tube Alloys alone?

If the Tizard Mission and Tube Alloys exchange had failed, could Britain still have built the bomb within a decade?

Probably, but Britain would have faced a much harder industrial programme without American safety, money, space, and infrastructure.

Britain could plausibly have produced an atomic bomb within a decade, but the industrial burden would have been immense. The United States offered safety from German bombing plus more space, money, and spare infrastructure for uranium processing and weapon production. German work also suffered from Nazi hostility to theoretical physics and a technical path that demanded impractical amounts of uranium. Scientific knowledge alone did not guarantee a wartime weapon without secure industrial capacity.