Overview
Although Operation Gold was planned by the SIS and the CIA, it was CIA money and manpower that carried it out. Details of the project are still classified, and whatever authoritative information can be found is scant. This is primarily because the then-Director of Central Intelligence, Allen Dulles ordered "as little as possible" be "reduced to writing" when the project was authorized.
According to one account, Reinhard Gehlen, the head of the Bundesnachrichtendienst, first alerted Dulles to the location of a crucial telephone junction, less than two meters (six feet) underground, where three cables came together close to the border of the American sector of West Berlin.
British and U.S. intelligence officials met in London to plan the tunnel. One of those who attended those early meetings was George Blake, a mole in the British intelligence apparatus. Blake apparently alerted the KGB immediately, for two of Gehlen's agents were caught trying to get a potential tapping wire across a Berlin canal.
The KGB decided to let Operation Gold go on since in order to attack the tunnel, the Soviets would have to compromise Blake and they found it preferable to sacrifice some information rather than their valuable agent. The KGB did not inform anyone in Germany, including the East Germans or the Soviet users of the cable lines, about the taps.
In December 1953 the operation was placed under the direction of William King Harvey, a former FBI official who transferred to the CIA. A warehouse with an unconventionally deep basement was specially constructed in the Rudow district of the American Sector of Berlin to serve as the staging area for the tunnel. The covert construction of a 450-metre (1,476-foot) tunnel 6 metres (~20 feet) under the world’s most heavily patrolled border to intersect a series of cable less than 47 cm (18") below a busy street was an exceptional engineering challenge. Digging the initial vertical shaft for the tunnel began on 2 September, 1954 and was completed on 25 February the following year. The tunnel ran underneath Treptow/Altglienicke in the Soviet Sector from an electronic box for the tapping of the wires in Neukölln/Rudow in the American Sector. There the British and the Americans listened and recorded messages flowing to and from Soviet military headquarters in Zossen, near Berlin; conversations between Moscow and the Soviet embassy in East Berlin; and conversations between East German and Soviet officials.
It appears the West was unable to break the Soviet encryption at this time. Instead they took advantage of a faint electronic echo produced by the Soviet communications equipment to read the traffic in plain text.
In Washington, DC, a team of CIA translators and analysts worked constantly on the vast amount of intercepts, ranging from high-level talk to barracks gossip. During the tunnel's brief lifespan of eleven months and eleven days, about half a million calls were recorded in 50,000 tapes. To evaluate this deluge the work of mining Operation Gold continued until September 1958. The KGB, forced to keep the flow of information as normal as possible, would occasionally let authentic sounding communications get through; the CIA may still have obtained some valuable information.
When Blake received a transfer in 1955, the Soviets were free to "discover" the tunnel. On 21 April 1956, eleven months after the tunnel went into operation, Soviet and East German soldiers broke into the eastern end of the tunnel; calling it a "breach of the norms of international law" and "a gangster act." Newspapers around the world ran photographs of the underground partition of the tunnel directly under the inter-German frontier. The wall had a sign in German and Russian reading "Entry is Forbidden by the Commanding General."
Not only was Allen Dulles affected by the tunnel raid, but also his brother John Foster Dulles, the Secretary of State, and his sister Eleanor Lansing Dulles, the State Department's desk officer for Berlin.
Only in 1961, when Blake was arrested, tried and convicted, did Western officials realize that the tunnel had been compromised long before construction had begun. Although Allen Dulles has publicly celebrated the success of Operation Gold, CIA analysts have argued about the overall worth of the intelligence that they had gathered. By one assessment, the Soviets had allowed ordinary military communications to flow through the cables to project the illusion that the Soviets had no aggressive intent against West Berlin.
Operation Gold forms the background to the novels The Innocent by Ian McEwan and Voices Under Berlin: The Tale of a Monterey Mary by T.H.E. Hill.
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