For most Americans, the British Security Service is something of a mystery. As they will learn from Defend the Realm, Christopher Andrew’s exhaustive but accessible new history, it has been something of a mystery to the British public as well. When, in 1957, politician R. A. Butler was appointed home secretary, a position whose responsibility includes oversight of the agency, he admitted that he had no idea how to find its headquarters. To his considerable surprise, it turned out to be based not in some highly secret location but in a perfectly conventional London office building known as Leconfield House. The agency, popularly known as MI5 (for Military Intelligence, Section 5), was then nearly fifty years old, but it would be another thirty-two years before its existence was officially acknowledged.
As intelligence authority Andrew explains, Britain had virtually no espionage apparatus at the beginning of the twentieth century. That the public (and perhaps even the country’s potential enemies) believed otherwise was due largely to the efforts of such novelists as William Le Queux and Rudyard Kipling, both of whom sang the praises of British superiority in the shadowy, far-flung world of espionage. In fact, Britain’s army and navy had only tiny intelligence components, while the Special Branch of the Metropolitan Police (MPSB), which had been set up to deal with Irish Republican terrorists, was only slightly larger.
However, change was imminent, propelled by the prospect of ever-increasing German militarization and the certain knowledge that Germany was introducing its own spies into England. In 1903, the director of military operations within the War Office established two new, albeit small, bodiesthen called MO2 and MO3to deal with foreign intelligence and domestic counterespionage, respectively. The Secret Service Bureau followed in 1909, and one of its components, MI5, took over the responsibilities of MO3 under the direction of Sir Vernon Kell. Thus Defend the Realm’s publication coincides with the centennial year of MI5’s formation.
Andrew divides the history of the agency into six periods. Before and during World War I (or the “Great War,” as the British remember it), the primary espionage threat came from German subversion. Between the wars, MI5 dealt with the “Red Menace” of communism, as well as the rise of fascism at home and abroad. During World War II, the immediate enemies were once again German agents, although the service was well aware that the Soviet Union, although ostensibly an ally, was also a threat. Andrew sees the events of the subsequent Cold War as falling into two periods, after which counterterrorism rather than counterespionage became MI5’s principal activity.
During World War I, MI5 staff devised a classification system for suspects that ran from AA (“Absolutely Anglicised” or “Absolutely Allied”) to B (“Boche,” a term for “rascal” borrowed from the French) andworst of allBB (“Bad Boche”). It was later determined that Germany had introduced some 120 spies into the country during the conflict, but some had simply pocketed their initial payment and made their way to the United States as immigrants. The service celebrated the 1918 armistice with a lighthearted “Hush-Hush” Revue and dinner dance. Subsequently, the agency’s strength fell to nearly prewar levels, only to rise again in the late 1930’s with the approach of another war.
Of the two directors and fourteen directors general who have run MI5, Andrew singles out Sir David Petrie (1941-1946) for special praise. Petrie took over the agency in 1941 during a period marked by serious disarray, poor morale, and uncertain leadership. By war’s end in 1945, he could boast that MI5 had completely neutralized German subversion. A large part of the effort involved the famous Double-Cross (or XX) System. Overseen by a committee of intelligence agents headed by Oxford don turned MI5 officer J. C. Masterman, this operation made use of decryptions from the German Enigma code machines to...
(The entire section is 1665 words.)