THE COLD WAREspionage in Cold War Berlin

Figure 1. The Glienicke Bridge, a.k.a. The Bridge of Spies, between Berlin and Potsdam was, used for to exchange of prisoners during the Cold War.

The Berlin Blockade, as it is now known, was resolved by supplying the city with food and raw materials through an impressive airlift.

As the Second World War ended, and Berlin was partitioned between the Allied Forces and the Soviets, tensions started rising between the two blocs. This paved the way for a practice that has now become a very prominent part of Berlin history and culture, namely espionage. Cultural references to espionage in spy novels, films, museums, and landmarks demonstrate how ingrained espionage is in Berlin culture. The espionage novels of John le Carré and their cinematic adaptations are prime examples, but in no way the only ones. But Berlin was not always a hub for spies, double agents, or secret operations. So how did a city devastated by war and divided in two opposing superpowers become the famous “capital of spies”?¹ What role did British Berlin play in the establishment of espionage as standard practice in Cold War? In this article we will examine the development of espionage in Berlin and how British Berlin reacted and asserted itself. We will also explore a very important secret operation and the man who changed the fate of that operation.

The devastation of the city was not limited to one particular sector. In all areas of Berlin buildings had been destroyed and families torn apart. While the sectors resembled each other in this respect, they differed in their political views. One sector—the Soviet sector—used its geographic advantage to develop its intelligence capabilities. West Berlin was like a small island in the vast sea of Soviet territory.

It was easy for the Soviets to extract information from West Berlin due to their geographic advantage, but also due to the Allied Forces’ prior efforts maintain a healthy relationship with the Soviets during the beginning of the occupation. These efforts resulted in slower development of the Allies intelligence practices.² Meanwhile, the Soviet army was “rapidly and systematically transforming the dividing line between their eastern zone and the western zone into a frontier between East and West.”³

The Soviets were able to pressure the Western forces on important political matters such as access to West Berlin as a result of the intelligence they had gathered in a short span of time. Initially the United Kingdom and United States were keen to avoid confrontation, as they feared damaging the wartime alliance with the Soviet Union. Yet this was short-lived. Despite the initial indifference of the Allied forces towards Soviet affairs, the Soviet Union’s interest in the East German uranium mines persuaded them to change their strategy. Both the Allied forces—particularly the United States—and the Soviets had already begun the race for atomic weapons, but the scale of the mining activities differed greatly between the two powers.

In East Germany, exploration for uranium started right after the Second World War. Mining operations began in the Erzgebirge (Ore Mountains) in 1946, later expanding to Ronneburg and other regions in Thuringia. The mining company, Wismut, was founded in 1947, and became a joint USSR-GDR company in 1954. The uranium produced was exported to the Soviets. It is estimated that more than 200,000 tons of uranium were produced by Wismut during the Cold War, which made GDR the third largest producer of uranium in the world.⁴ In West Germany, uranium mining began much later and was never as productive as in the East. There were fewer suitable mining regions, and these were eventually abandoned due to economic reasons.⁵

Stalin’s nuclear project started to gain momentum and the Allied intelligence bases in West Berlin, had none of the advantages of their Soviet counterparts when they were first established. Yet in a few years they developed sources and networks capable of carrying vital information from East Berlin to West Berlin.  Allied Forces became capable of undertaking major and complex operations.

Operation Stopwatch

In the late 1940s the Soviets shifted their main secure communication channels from wireless radio transmissions to landlines, making Vienna and Berlin the centre of their communication systems. This shift caused serious loss of valuable intelligence for the Allied forces, especially for the CIA and the SIS (British Secret Intelligence Service).⁶ Two different types of landlines were being used: overhead lines strung on telephone poles and buried cables, respectively.⁷ While the former was almost impossible to tap, the latter was not.  The SIS first tapped into the new landline communications in Vienna in an operation known as Operation Silver, which ran from 1949 to 1955. When the CIA revealed that they too were planning a similar operation in Berlin, the SIS revealed their Vienna operation and the two countries collaborated on Operation Stopwatch (known as Operation Gold by the Americans). The goal of this operation was to tap into the landline communications of the Soviet Army headquarters by using a tunnel.

Operation Stopwatch was “one of the most valuable and daring projects ever undertaken” in West Berlin.⁸ After the then-director of the CIA, Allen Dulles, approved the operation on 20 January 1954, the construction of the tunnel began. A West Berlin contractor started the construction thinking it was a warehouse with unusually big basements and ramps to accommodate a new and improved warehouse design. To the naked eye, the tunnel looked like a normal conventional radar or Electronics Intelligence Station, an intelligence gathering compound which uses electronic sensors.⁹ The construction of the entire tunnel, including the tap chamber, was completed in March 1955. According to the CIA Museum, almost 3,100 tons of soil were removed during the construction, and 125 tons of steel plate and 765 cubic metres of grout were used.  The finished tunnel was 450 metres long. As the final step, the British technicians installed the taps, and intelligence collection began in May 1955.¹⁰

Despite the enormous intelligence effort and the hours of telephone conversations tapped, the value of the information gathered is disputed. It was later discovered that the Soviets were aware of this operation even before its construction began, but feigned ignorance in order to protect George Blake—an MI6 operative who was also a Soviet spy.

George Blake

George Blake’s first known interaction with the Soviets was in 1950, when he was a prisoner in North Korea.¹¹ Previously, he had been a sub-lieutenant in the Royal Navy and was recruited by the MI6 in 1944. Four years later he was sent to Seoul posing as a vice-consul, to gather intelligence on Communist North Korea, China, and the Soviet Far East. When the Korean War broke out on June 1950 and the UK sided with the South, Blake and the other diplomats were taken prisoner. He was then recruited as a spy by the Soviets, to infiltrate British operations.

Although Blake eventually became a very important figure in the Berlin intelligence operations, his activities did not start in Berlin. After being released from North Korea and returning to London, he met many times with Sergei Aleksandrovich Kondrashev, a KGB agent, to whom he passed on information in order to prove his worthiness. Kondrashev was unknown to British intelligence. His cover was as an employee at the Soviet Embassy in London, and he had operational experience in surveillance and countersurveillance techniques.¹² In 1955, Blake was assigned to the British military government in Berlin. Here, he had even more access to valuable information on the SIS.

The Soviet Union was aware of Operation Silver and Stopwatch before they were even officially approved by their intelligence agencies.¹³ However, if they were to act in order to stop the operations, they would have compromised Blake. According to Arseny Vasilievich Tishkov, the foreign intelligence service deputy chief, believed that even feeding the British and American intelligence false information would possibly jeopardise Blake.

Blake was arrested in London in 1961 due to suspicion of treason and he made a full confession. He was sentenced to 42 years in prison, which was the longest term ever sentenced by a British court to that day, excluding life terms. However, the Blake did not spend 42 years in Wormwood Scrubs. He escaped from prison five years later with the help of three other prisoners, Michael Randle and Pat Pottle, who were radical anti-nuclear campaigners and Sean Bourke, an Irishman who was imprisoned after sending a homemade bomb to a police officer. Blake has been living in Moscow ever since.

Figure 5. George Blake in the 1950s.


The extent of the damage caused by George Blake and the value of the information gathered by Operation Stopwatch remain unknown, since the details were never fully disclosed to the public. Nevertheless, the stories of the spy tunnel and the double agent have heavily influenced Berlin’s culture and history. To this day, it is possible to see fragments of the spy tunnel and observe the Cold War symbol in person.¹⁴ George Blake’s actions have shaped the course of the Cold War in Berlin, in Germany, and worldwide.

“The Capital of Spies in Cold War Berlin,” Deutsches Spionagemuseum, n.d.,; David E. Murphy, “Spies in Berlin: A Hidden Key to the Cold War,” Foreign Affairs 77, no. 4 (1998).; Ibid. 172.; Manuel Schramm, “Uranium Mining and the Environment in East and West Germany,” RCC Perspectives, no. 10 (2012): 73.; Ibid. 74.; David E. Murphy, Sergei A. Kondrashev, and George Bailey, “The Berlin Tunnel: Fact and Fiction,” in Battleground Berlin: CIA vs. KGB in the Cold War (London: Yale University Press, 1997): 208.; Ibid.; David Stafford, Spies Beneath Berlin. (London: Thistle Publishing, 2013).; Ibid.; n Tunnel,” Central Intelligence Agency, June 23, 2012,; Murphy, Kondrashev and Bailey, “The Berlin Tunnel: Fact and Fiction”, 214; Ibid. 214-215.; Stafford, Spies Beneath Berlin.; “Highlights,” Alliierten Museum, n.d.,

Figure 1: The Glienicke Bridge, a.k.a. The Bridge of Spies, between Berlin and Potsdam was, used for to exchange of prisoners during the Cold War © AP Photo / Werner Kreusch
Figure 2: The Glienicke Bridge © BY 2.0 David Stanley / Flickr
Figure 3: The Glienicke Bridge © Wikimedia Commons
Figure 4: Tapping equipment at the end of the Tunnel ©  Daily Mail
Figure 5: George Blake in the 1950s © Wikimedia Commons

“Highlights.” Alliierten Museum, n.d. URL:; Murphy, David E. “Spies in Berlin: A Hidden Key to the Cold War.” Foreign Affairs77, no. 4 (1998); Murphy, David E., Sergei A. Kondrashev, and George Bailey. “The Berlin Tunnel: Fact and Fiction.” In Battleground Berlin: CIA vs. KGB in the Cold War. London: Yale University Press, 1997; Schramm, Manuel. “Uranium Mining and the Environment in East and West Germany.” RCC Perspectives, no. 10 (2012); Stafford, David. Spies Beneath Berlin. London: Thistle Publishing, 2013; “The Berlin Tunnel.” Central Intelligence Agency, June 23, 2012. URL:; “The Capital of Spies in Cold War Berlin.” Deutsches Spionagemuseum, n.d. URL: