History tells us that the Second World War broke Britain as a great power, diminishing its military strength, ruining its economy, and precipitating a striking wave of decolonization. Nationalists and new superpowers dominated the post-war landscape, and the country was on the slide. But no one knew this in 1945—the leading politicians, the top civil servants, and the most knowledgeable experts, all expected the British Empire to remain intact long into the future.

How do we account for the difference between what it was thought would happen and the actual course of events? Superpower Britain is the first book to focus in depth on this fascinating counterpoint and to fully integrate the history of Britain and the effects of the Second World War with the history of the British Empire. It explains what the British planned to do in the post-war world, why they thought their plans for regeneration and the future world order were viable, and what the war had actually done to British world power and its imperial foundations.