them that the CIA failed to tell British authorities everything it did in London. Yet he remained fascinated by the secret world, and valued the intelligence machinery in Downing Street, engaging in academic debate with his intelligence analysts on points of detail like the Oxford junior research fellow he once was.
Intelligence imperilled more than one British prime minister. Within weeks of her arrival at Downing Street, Margaret Thatcher insisted on sitting in with the Joint Intelligence Committee to better understand how intelligence was prepared for those at the top. Only three years later, a major intelligence failure by the same mechanism over the Falkland Islands almost ended her government. John Major found himself confronted by the Arms to Iraq affair, in which ministers had sought to cover up the control of arms export companies by MI5 and MI6. The subsequent inquiry by Lord Scott revealed only part of the murky tale, and brought Major’s government close to defeat in the House of Commons. Tony Blair’s era was defined by vicious public arguments over intelligence. Despite his successful use of secret service during the creation of the Good Friday Agreement in Northern Ireland, it was accusations of the misuse of intelligence over Iraq that would leave his reputation in tatters. His bold decision to use intelligence publicly to justify the war on Iraq quickly backfired, and by 2005 the missing WMD fiasco threatened to end his government prematurely. Blair’s administration also left a toxic legacy of allegations about complicity in torture with which Gordon Brown and David Cameron have both struggled. Most recently, the deluge of secrets revealed by NSA contractor Edward Snowden has reshaped relations between David Cameron, Barack Obama and other world leaders including Angela Merkel. In an era when secret services are increasingly kept in check by whistleblowers and their remarkable revelations, British prime ministers live in constant fear of intelligence ‘blowback’.
For good or ill, intelligence matters to prime ministers. It may be only one factor shaping their thinking, but it can be critical and very personal, often revealing what their opponents think about them.2 Intelligence can provide warning of dangerous future events, and has certainly averted major terrorist attacks on London. It can help to prevent wars, or – once they begin – mean the difference between victory and defeat. Yet it can also be misused to justify preconceived policy desires. The secret world can help to resolve a prime minister’s most difficult dilemmas by providing a hidden hand that shapes events behind the scenes. It can also become a seductive apparent panacea, whereby secret service is employed to carry out a leader’s dirty work, at home and abroad. In its darkest moments, intelligence can consume prime ministers.
The relationship has become ever closer. The link between Number 10 and Britain’s intelligence agencies, as intimate as it is secret, lies at the heart of the British establishment. For almost a century, a stream of secret boxes – red for MI6 material and blue for intercepted communications from GCHQ – made their way to 10 Downing Street. Sifted by the cabinet secretary, the best material was placed in a special striped box, nicknamed ‘Old Stripey’, for the early attention of the prime minister. Since the creation of Britain’s intelligence agencies in 1909, the relationship between prime ministers and the secret world has moved from circumspection to centrality. One thing is clear from this story. Intelligence is not about rogue agents operating wildly and freely; nor is it an unaccountable business far removed from the corridors of political power. Many of the most hair-raising intelligence activities and many of the most dangerous covert operations have involved Number 10 directly. Intelligence is part of the beating heart of Britain’s core executive, and has long held a special place behind the famous black door of 10 Downing Street.
The use of secret intelligence is one of the dark arts of statecraft. Yet during the early years of the twentieth century, British prime ministers were notably inept practitioners. Relative strangers to the murky world of espionage and clandestine warfare, they treated the subject with either indifference or outright suspicion. When prime ministers did draw on intelligence, they demonstrated remarkable inexperience and naïvety in its use. While Herbert Asquith presided over the creation of the modern British intelligence services in 1909, he had little interest in secret matters other than his mistress. David Lloyd George and Stanley Baldwin enjoyed the first fruits of Britain’s revived wartime codebreaking operations, but squandered them by publicising not only German but also American and Russian intercepts, compromising the source and causing anguish among the denizens of secret service. Ramsay MacDonald, Britain’s first Labour prime minister, distanced himself from the secret services, fearing they may have been out to plot the demise of his government; while Neville Chamberlain arrogantly ignored invaluable secret intelligence provided by brave Germans who personally visited Downing Street at the risk of their own lives. Instead, he preferred to rely on diplomatic reports from those sympathetic to Hitler, which reinforced his own preconceptions.
In 1940, Churchill changed all this. Indeed, a Churchillian revolution in intelligence occurred during the middle of the twentieth century. For five years Britain’s fate hung in the balance, and intelligence, especially Ultra material provided by Bletchley Park, often proved the operational advantage. Churchill placed a premium on intelligence chiefs telling truth to power: he believed that craven intelligence officers accounted for some of Sir Douglas Haig’s failings during the First World War. ‘The temptation to tell a Chief in a great position the things he most likes to hear,’ Churchill later observed, ‘is one of the commonest explanations of mistaken policy.’3 As prime minister he developed close links with the secret world, especially through Stewart Menzies, chief of MI6, whom he sometimes summoned to his bedside in the middle of the night. The prime minister was obsessed with secret intelligence, and – more importantly – strained every sinew to make sure that the government used it to efficient purpose.
Churchill was impulsive, and so constituted a mixed blessing. As David Reynolds argues in his magisterial study, there were reasons why both Baldwin and Chamberlain had kept him out of office. He had imagination, industry, energy and eloquence, but he lacked judgement and wisdom. Lloyd George was of much the same opinion, arguing that in an emergency Churchill’s vision and imagination were essential, and should be used to the full, but at the same time he should be kept under a ‘vigilant eye’.4 Churchill’s over-enthusiasm led to friction with the chiefs of staff, who had the onerous duty of vigilance, and indeed to occasional blunders. Yet his determination to harness the power of intelligence transformed not only the centre of government, but also the very nature of British statecraft.5
Uniquely, Churchill brought with him vast intelligence experience. In charge of the Admiralty during the First World War, he had seen the work of Britain’s most proficient codebreakers at first hand. In the interwar years he had been deeply interested in intelligence, and repeatedly shaped its development. Once he became prime minister in May 1940, he was finally empowered to change procedure at the top. He demanded raw intelligence fresh from MI6 agents in the field or from Bletchley Park. This annoyed the chiefs of staff, and triggered a revolution in Whitehall’s intelligence assessment machinery – the Joint Intelligence Committee moved centre stage – laying the foundations of the successful body which still operates today. Moreover, the impetuous Churchill loved action. He not only nurtured Number 10’s direct connection with espionage, but also encouraged a new focus on special operations and covert warfare. His personal interest in ‘funnies’ and oddball units – ranging from the Chindits and the Commandos to the Special Operations Executive and most famously the SAS – changed how Britain approached warfare for decades to come.6
Churchill’s wartime government was itself a school for secret service. Around him, Britain’s future leaders learned the business of intelligence and its importance to the practice of statecraft. Thereafter, Britain’s next few prime ministers – all veterans of Churchill’s wartime government – understood the value of secret sources and the event-shaping power of intelligence. Trained in the sophisticated integration of intelligence and policy, his successors realised that it formed a crucial instrument for any leader in a perilous period of British decline. Secret service was part of the ‘fancy footwork’ of retreating empire that could potentially turn the tide in colonial bushfire wars, gain an upper hand in manoeuvrings against the Soviets,