IN 1938 IT became common knowledge that it was feasible, as opposed to just theoretically possible, to build an atomic bomb. However, the Nazis thought that the war would be over by the time they could build their bomb and that the enormous resources required would be better utilised developing conventional weapons. Although many scientists had fled Germany, the Allies feared that the Germans were still capable of manufacturing an atomic bomb, and so on 24 September 1941 the British War Cabinet, at a lengthy meeting chaired by Churchill, decided that Britain should go it alone and build thirtysix atomic bombs of her own. Within nine days of this meeting, its minutes were being read by Stalin. Such was the extent of Soviet penetration at every level of the British political and scientific establishment, and eventually inside the Manhattan Project itself, that the USSR was able to explode an atomic bomb in August 1949, some years ahead of US predictions.

Ultimate Deception is the shocking story of ths infiltration. No detail is spared in describing how the NKVD and GRU recruited and ran their spies. In addition to the usual suspects (Blunt, Philby, Burgess, Maclean, Cairncross, Fuchs, etc), it alleges that StafTord Cripps, Harold Wdson, Victor Rothschild, Robert Maxwell and