Engulf, Operation

Engulf, Operation


Engulf was a series of operations whereby the British Security Service, MI5, intercepted Egyptian and French cipher transmissions during a period from the mid-1950s to the mid-1960s. The first major operation of Engulf took place during the Suez crisis of 1956, when a team led by British spymaster Peter Wright planted a bug in the cipher room of the Egyptian embassy in London.

The Suez crisis began in July 1956, when Egyptian president Gamal Abdel Nasser seized the Suez Canal, formerly under the control of Britain and France. Britain and the United States, well aware of Nasser's increasingly close ties with the Soviet Union, had refused to fund Nasser's plans to build the Aswan High Dam. Therefore, Nasser took over the canal, not only as an act of retaliation, but as a means of raising money by collecting the tolls charged to ships passing through the canal. Britain and France, in a plan orchestrated with Israel, forced the evacuation of Egyptian troops, but were ultimately forced to themselves evacuate by the threat of United Nations or Soviet intervention.

In the months leading up to the crisis, MI5 undertook efforts to plant a listening device (bug) in the Egyptian embassy. The British postal service, which controlled telephone service, deliberately created problems with the embassy's phones, and an MI5 undercover team arrived under the guise of repairing the equipment. While there, they planted bugs that allowed them to hear the noises made by the setting of the machines. Skilled specialists were able to translate these noises into usable intelligence.

An unexpected conduit from Moscow to London. As Wright later recalled in his autobiography Spycatcher, intercepting the Egyptian cipher transmissions allowed MI5 to follow discussions between the Egyptians and Soviets in Moscow, the specifics of which were regularly passed on to the embassy in London. From these transmissions, the British learned that the Soviets were not simply bluffing when they threatened to intervene in Suez on the Egyptians' behalf.

Wright went on to recount that the Soviets helped their Egyptian allies by sweeping the London embassy for bugs, but when they discovered the device planted by MI5, they opted to leave it in place and not inform the Egyptians. By allowing MI5 to listen in to the Egyptian embassy, the Soviets were able to convey exactly where they stood on the Suez situation, and to do so in such a way that the British would know that they meant what they were saying.

Other phases. In later phases of Engulf, MI5 attempted to detect cipher noises in other contexts. In 1959, for instance, while the Soviet cruiser Ordzhonikidze was moored at Stockholm, Sweden, MI5 placed microphones in a nearby warehouse. This time, of course, there was no question of going aboard the ship under any pretext to plant a bug, and as it turned out, the warehouse was not close enough. Though MI5 did pick up what were apparently cipher machine noises, this did not lead to any usable intelligence.

From 1960 to 1963, in an operation known as Stockade, MI5 listened in to the French embassy in London. Unlike the Suez phase, however, reliable intelligence did not give the British any real diplomatic benefit. The United Kingdom was attempting to join the European Economic Community (EEC) or Common Market, which in 1993 would become the European Union. France was attempting to keep Great Britain out of the EEC, and the bugging simply revealed that the French were not going to budge, without revealing any likely means of inducing them to do so. Wright, who also led Stockade, later recalled that the operation "was a graphic illustration of the limitations of intelligence."



Aldrich, Richard J. The Hidden Hand: Britain, America, and Cold War Secret Intelligence. Woodstock, NY: Overlook Press, 2002.

Epstein, Leon D. British Politics in the Suez Crisis. Urbana: University of Illinois Press, 1964.

Kelly, Saul, and Anthony Gorst. Whitehall and the Suez Crisis. Portland, OR: Frank Cass, 2000.

Louis, William Roger, and Roger Owen. Suez 1956: The Crisis and Its Consequences. New York: Oxford University Press, 1989.

West, Nigel. The Circus: MI5 Operations 1945–1972. New York: Stein and Day, 1983.

Wright, Peter. Spycatcher: The Candid Autobiography of a Senior Intelligence Officer. New York: Viking, 1987.


Cipher Machines
Egypt, Intelligence and Security
MI5 (British Security Service)
Special Relationship: Technology Sharing Between the Intelligence Agencies of the United States and United Kingdom
United Kingdom, Intelligence and Security

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