The nuclear weapons question runs through post-1940 British history like an irradiated thread. It represents part of the hidden history of twentieth-century Britain, given the high level of technical secrecy and political sensitivity in which the bomb was - and is - embedded. This volume publishes previously classified Cabinet papers and related archives, dealing with the first theoretical scientific breakthrough in 1940, through the A-bomb and H-bomb procurements, to the Polaris missile upgrading decisions of the 1970s. The story is brought up to date in Peter Hennessy's narrative, which covers developments up to the spring of 2007. The fascination of the book lies in its uncovering the very private internal themes, debates and justifications for Britain's being a nuclear weapons power exchanged between ministers, civil servants, diplomats, scientists, military and intelligence officers. There is a strong element of now-it-can-be-told in the book, which will appeal not just to professional historians but also to undergraduates and A-Level students who are partaking in the current mini-boom on the study of the Cold War. Cabinets and the Bomb is also a contribution to wider public understanding in the context of the present debate about Trident upgrade (though it is a book of explanation, not advocacy).