CAB 158, Ministry of Defence and Cabinet Office: Central Intelligence Machinery: Joint Intelligence Sub-Committee later Committee: Memoranda (JIC Series), 1946-1968

This series contains the memoranda issued by the Joint Intelligence Committee (Joint Intelligence Sub-Committee until December 31, 1947). Some 1947 and 1948 memoranda carry an “(O)” suffix indicating that they were concerned with operational matters.

The records in this series which have been included in the resource span the period from January 1947, when the Joint Intelligence Sub-Committee (JIC) was reconstituted after the end of the Second World War, to December 1953. The subject matter covered in the papers reflects the wide range of Britain’s military responsibilities during this period, from the role of the colonies in wartime, to Jewish immigration into Palestine, to anti-British activities in the Middle East. Of particular importance to the JIC were the Soviet threat and the likelihood of war. Initial estimates made in 1947, which can be found in CAB 158/1, were concerned primarily with the Soviets’ acquisition of atomic weapons. The JIC report, Forecast on the World Situation in 1957, a forty-nine-page report circulated to the Chiefs of Staff in 1948 that looked forward ten years, concluded that the Russians could produce their first plutonium atomic bomb by January 1951 and by 1953 could hold a nuclear stockpile of 6-22 nuclear weapons.[1] Subsequent estimates concentrated on the Red Army’s superiority in conventional forces and assessments of whether the Soviets would use this advantage to overrun Western Europe and the Middle East. The JIC paper covering Soviet intentions and capabilities circulated in 1947 cautioned that although Moscow would not deliberately provoke hostilities, the Soviet leadership would pursue their objectives by all means short of war. However, if war broke out there was concern that the Soviet forces would “achieve rapid and far-reaching successes against any likely combination of opposing land forces” and could reach the Atlantic coast within forty days.[2] This alarmist conclusion was shared with the United States and proved pivotal in the eventual creation of the North Atlantic Treaty Organization (NATO) in 1949.

In assessing the likelihood of war, the JIC concluded that the possession of the atomic bomb by the United States was a major factor in deterring Soviet leaders from pursuing their objectives by military as opposed to cold war methods. The JIC believed that although the ultimate aim of the Soviet leadership was the elimination of capitalism, this would be a long revolutionary struggle, and its immediate aim was the security of the Soviet Union. Given this assessment, the JIC concluded that a major confrontation with the West would not occur until the Soviets obtained a credible nuclear strike force of their own. Before this new balance of forces was achieved, Soviet strategy would be reliant “on a basis of Communist penetration aided by economic distress, rather than on a basis of overt aggression; or, in other words, by cold war methods rather than by real war.”[3]

These assumptions were thrown into doubt following news of the Soviets’ first nuclear test in August 1949. The Soviets’ acquisition of nuclear weapons much earlier than expected led to a revision of all military and intelligence assessments. It was feared that the Soviet Union might even attempt a surprise nuclear attack. Meeting in June 1950, the JIC considered a paper, which can be found in CAB 158/9, on the possibility of a Soviet nuclear weapon being smuggled into the country aboard a merchant ship and detonated by remote control or time delay in central London.[4] The general alarm in the West was compounded by the communist victory in China and the outbreak of the Korean War in June 1950. The JIC believed that there was “no likelihood of the communists being checked on the mainland of China.”[5] It further contended that the communist forces would seek to unify the country by defeating the nationalist forces of Chiang Kai-shek which had retreated to the island of Formosa (modern-day Taiwan). These events suggested that the Soviet Union was willing to follow a more aggressive foreign policy. To some commentators, particularly those in the United States, the military action in Korea was regarded as a ruse designed to divert attention from a possible Soviet advance on Berlin. The JIC were skeptical and did not believe that North Korean aggression was launched with the primary objective of diverting American attention from Europe or as a prelude to Soviet military action in the Middle East or Europe. The assessment, which can be found in CAB 158/11, concluded that the North Korean invasion was “a limited operation within the ambit of an intensified drive to expel western influence from the whole of the Far East and South East Asia.”[6]

The death of Stalin in 1953 led the JIC to reassess the degree of Soviet control over Eastern Europe. One area of particular interest was the disturbances in East Germany in June 1953. To assess the possible consequences of the civil unrest, the JIC produced a paper which can be found in CAB 158/16. The paper concluded that the origins of the riots lay in deep-rooted social and economic discontent which by a series of miscalculations by the communist government had been allowed to develop into serious trouble. Although the East German government blamed the disturbances on “Fascist provocateurs” the JIC contended that they were undoubtedly spontaneous and came as a great shock to the Soviet Government.[7] It was further believed that it would take a long time for the East German government to restore its prestige but that the disturbances were unlikely to spread to other Eastern European countries such as Poland and Hungary.

These early JIC reports offer a unique insight into Britain’s diplomatic and military role in the immediate aftermath of the Second World War and provide an invaluable documentary source charting the early development of the Cold War in Europe, Asia, and the Middle East.


Dr. Stephen Twigge, Head of Modern Collections, The National Archives, UK

[1] CAB 158/1, Joint Intelligence Sub-Committee: memoranda 1-50; JIC (47) 42 (O) (Final), Forecast of World Situation in 1957, June 12, 1948.
[2] CAB 158/1, Joint Intelligence Sub-Committee: memoranda 1-50; JIC (47) 7/2 (Final), Soviet interests, intentions and capabilities, August 6, 1947.
[3] CAB 158/3, Joint Intelligence Committee: Memoranda 1-44; JIC (48) 9, Russian interests, intentions and capabilities, July 23, 1948.
[4] CAB 158/9, Joint Intelligence Committee: memoranda 1-30; JIC (50) 21 (Final), Clandestine use of atomic weapons, June 12, 1950.
[5] CAB 158/8, Joint Intelligence Committee: memoranda 71-118; JIC (49) 103 (Final), Chinese communist intentions and capabilities, November 2, 1949.
[6] CAB 158/11, Joint Intelligence Committee: memoranda 65-114; JIC (50) 75, Probable Soviet short term developments, August 23, 1950.
[7] CAB 158/16, Joint Intelligence Committee: memoranda 63-122; JIC (53) 68 (Final), Disturbances in East Germany, September 4, 1953.
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