After 1945, Western capitals were dominated by the fear of a "Nuclear Pearl Harbor". Atomic bombs, new biological and chemical weapons, and ballistic rockets such as the V-2 against which there was no defence, combined to create an atmosphere of deep menace. The urgent need for better warning systems allowed the Western intelligence community to grow to unprecedented size and power. Meanwhile, under the precarious ceiling of nuclear deterrence, London, Washington, Moscow and Peking all sought new ways to play out their struggle. For these too they turned to the secret services, who developed further the clandestine operations evolved in the Second World War, such as underground armies, radio warfare, economic destabilization and cultural subversion. "Hidden hand" conflict, though, proved nothing less than explosive. Bitter arguments over provocation threatened to tear Western capitals apart. By 1952 the CIA was accusing the British SIS of "fouling up their operations" in the Eastern Bloc. Meanwhile, many in London had come to regard the Americans as bent on provoking a Third World War. Documents sent to Churchill and Attlee, revealed for the first time in this book, show that British intelligence chiefs believed the American military had set a target date for a war in which Britain would be obliterated. The key aim for Britain was not to contain the Soviet Union but rather to prevent a hot war provoked by the US Air Force and the CIA. Despite military decline, Britain maintained her status as a secret service world power for far longer than anyone suspected, so her intelligence contribution allowed some influence over her volatile partner, as well as guiding Prime Ministers in the fancy footwork of imperial retreat. The "hidden hand" also helped American Presidents - faced with the glass ceiling on American power created by nuclear weapons, and the need to coerce a disconcerting number of troublesome neutrals - to square some difficult circles. Above all, the American secret service allowed continual extension of Presidential power over foreign policy. Only with a new climate of revelations in the mid-1960s was the "golden era of special operations" brought to an end.