The Mole in the Garden

On a summer day in 1953, a posting order arrived at Secret Intelligence Service headquarters. Typed on Foreign Office stationery and routed through standard channels, this document listed George Blake’s name, his grade, and his reporting date for the Berlin station. A clerk filed a copy; another went to station chief Peter Lunn; a third remained in Blake’s personal file among papers recording his recruitment, training, and the notation of his North Korean captivity. The ledger of his assignment offered no ambiguities about what it contained, nor did it record what had happened to him as a prisoner or that he had already begun working for the Soviet Union.

The posting order itself was routine. Blake was a case officer, trained in Russian, experienced in the field, available for assignment. Berlin needed Russian speakers. The station there had expanded since the war’s end, and its responsibilities had grown with the city’s importance as an intelligence battleground. Lunn had requested additional personnel. Headquarters approved. Blake’s name appeared on the list of candidates, and the selection process moved forward with the quiet efficiency of bureaucratic procedure. No one objected. No one raised concerns. The file contained nothing that would have prompted a second look.

The confidence the service placed in Blake was not accidental. He had earned it through a biography that seemed, on its surface, to exemplify the qualities the Secret Intelligence Service sought. Born in Rotterdam in 1922 to a Dutch mother and an Egyptian father who had taken British nationality, Blake spent his childhood in the Netherlands. His father, Albert Behar, had served in the British Army during the First World War and had received a commission. The family moved frequently, following Albert’s postings, but George returned to the Netherlands for his schooling. He was, by upbringing, a cosmopolitan: fluent in Dutch, comfortable in French, familiar with the movements of military families across borders.

When the German Army invaded the Netherlands in May 1940, Blake’s path intersected with the war. He made his way to Britain, traveling through occupied France and neutral Spain before reaching Gibraltar and then London. The journey demonstrated qualities intelligence officers later noted: resourcefulness, determination, the ability to move through hostile territory without detection. In London, he contacted the Dutch government-in-exile and offered his services. He was eighteen years old.

The Dutch intelligence service, operating alongside British authorities, accepted him. He underwent training and was assigned to work on matters related to the Netherlands and its occupied population. His language skills made him valuable. His background gave him access to networks of informants and escape routes. The work was dangerous and demanded commitment. Blake performed well. His superiors noted his intelligence, his discretion, his willingness to take risks. When the war ended, he had established himself as a promising operative with a record that recommended him for further employment.

The Secret Intelligence Service approached him in 1946. The war had depleted its ranks and expanded its responsibilities. The emerging confrontation with the Soviet Union required officers who understood the continent, could operate in multiple languages, had demonstrated loyalty under pressure. Blake fit the profile. He underwent standard vetting procedures, which checked his background, his associations, his political affiliations. Nothing emerged that would have disqualified him. His wartime service had been honorable. His family background, while unconventional, raised no flags. His politics, insofar as the vetting process could determine them, were sound. He was, in the language of personnel files, a suitable candidate.

The service sent him to Cambridge, to the Joint Services School for Linguists, where he studied Russian. The school had been established to train officers in languages the post-war world demanded. Russian was the priority. The Soviet Union had emerged from the war as the primary adversary, and intelligence services needed officers who could read its documents, listen to its transmissions, interrogate its defectors. Blake excelled. His aptitude for languages, already evident in his Dutch and French, extended to Russian. He completed the course and received certification. The service now had a Russian speaker of proven ability and tested loyalty.

The posting that followed demonstrated the trust the service placed in him. In 1948, he was sent to Seoul, attached to the British legation under diplomatic cover. His official title was vice-consul. His actual mission was intelligence collection: gathering information on Communist North Korea, Communist China, and the Soviet Far East. The Korean peninsula was a frontier of the emerging Cold War. Blake arrived on November 6, 1948. He was twenty-six years old, running an intelligence station in a city that would soon become a war zone.

The Korean War broke out in June 1950. North Korean forces crossed the 38th parallel and advanced south, overwhelming defenders and pushing toward Pusan. Seoul fell within days. The British legation, along with other diplomatic missions, found itself trapped behind enemy lines. North Korean authorities interned the diplomatic staff, including Blake. He was now a prisoner of war, held in conditions that varied with the fortunes of the conflict and the whims of his captors.

The internment lasted more than two years. During that time, Blake underwent an experience he later described as transformative. The details of what happened in captivity remain contested. Blake himself, in his later confession and trial, provided an account emphasizing ideological conversion. He said he had witnessed the bombing of Korean civilians by American aircraft, that he had been impressed by the dedication of his Communist captors, that he had come to see the Soviet Union as the only force capable of opposing American imperialism. The conversion, he claimed, was genuine. He had become a Communist.

Soviet intelligence saw an opportunity. Blake was not merely a convert; he was a trained intelligence officer with access to British secrets. The KGB, through intermediaries, made contact. The circumstances of the approach remain unclear—whether Blake initiated contact or the Soviets identified him as a potential asset—but the result was a meeting. Blake agreed to work for the Soviet Union. He would return to British service as a mole, passing information to his handlers and concealing his true allegiance from colleagues.

The conversion narrative Blake later provided has been treated with skepticism by some historians. The timing of his approach to the Soviets, or their approach to him, cannot be independently verified. The conditions of his captivity— isolation, pressure, uncertainty—created an environment where ideological shifts were possible, but so were calculations of survival. Blake may have been a genuine convert; he may have been a pragmatic opportunist; he may have been something between. The documents do not settle the question. What the documents establish is that he emerged from captivity as a Soviet agent, and that he concealed this fact from British authorities who welcomed him home.

The return came in 1953. Blake landed at RAF Abingdon, where he was received as a hero. He had been a prisoner of the North Koreans for more than two years. He had survived. The service treated him as a returning officer who had endured hardship in the line of duty. There were questions about his captivity—the standard debriefings any released prisoner underwent—but those questions focused on what he had learned about the enemy, not on whether the enemy had turned him. The possibility of ideological conversion, or recruitment by hostile intelligence services, was not seriously considered. Blake’s background, his wartime service, his record of loyalty provided a protective shield. The vetting system had already cleared him. The assumption was that he remained the man he had been before.

The service gave him time to recover. He married in October 1954, wedding Gillian Allan, an MI6 secretary, at St Mark’s Church on North Audley Street in London. The marriage was a social event within the service, attended by colleagues who knew Blake as a promising officer who had suffered for his country. The ceremony reinforced his standing. He was now not merely an employee but a member of the service’s extended family. The bond of marriage, like the bond of shared service, created ties that seemed to guarantee loyalty.

The posting to Berlin came in 1955. The station there had become a center of operations against the Soviet Union and its East German satellite. The city’s division, the presence of Allied forces, the intensity of intelligence activity made it target-rich for officers on both sides of the Cold War. Blake’s Russian language skills made him valuable. His experience in Korea, gathering intelligence on Communist forces, seemed relevant. The service needed case officers who could handle a station expanding its operations and deepening cooperation with the American Central Intelligence Agency.

The tunnel project was already under discussion. Initial planning meetings had been held at No. 2 Carlton Gardens in London, beginning in late 1953. The Americans had proposed a joint operation to tap Soviet military communications in Berlin. The British had experience with such operations: Operation Silver, which ran from 1949 to 1955, had successfully tapped Soviet landline communications in Vienna. The Vienna operation, conducted jointly with Americans, had provided valuable intelligence and demonstrated the feasibility of large-scale technical interception. When the CIA proposed a similar operation in Berlin, the British brought their expertise from Operation Silver to the table. The resulting agreement was that the US would supply most of the financing and construct the tunnel, while the British would use their expertise to tap the cables and provide the electronic equipment.

Blake arrived in Berlin as these discussions advanced. His position as case officer gave him access to information about station operations, including tunnel planning. The extent of his knowledge at any given moment is difficult to determine from available documents. The planning process involved multiple layers of clearance, and not every officer would have been briefed on every detail. But Blake was not peripheral. He was a Russian speaker, a case officer with responsibilities for running agents and gathering intelligence, a member of a station central to the Secret Intelligence Service’s operations against the Soviet Union. He was, by virtue of position, inside the circle.

The Soviet Union now had an asset in precisely the location where the West was planning its most ambitious intelligence operation. The KGB faced a choice. It could expose Blake immediately, extracting whatever information he could provide and sacrificing him to preserve secrecy of other operations. Or it could keep him in place, using him as a long-term source and accepting risk that he might eventually be discovered. The decision would have far-reaching consequences for the tunnel operation and for broader Cold War intelligence history.

The documents recording Blake’s posting to Berlin do not hint at any of this. They are administrative papers, concerned with grades, salaries, reporting dates. The posting order that placed him in the station listed his name and duties. The station roster recorded his arrival. The personnel file noted his assignment. The papers were routine, and their routine nature was precisely what concealed the significance of what they represented. A man recruited by the Soviet Union was now embedded in the station planning an operation against it.

The systemic vulnerability Blake represented was not merely individual failure. It was a product of expansion intelligence services had undergone during and after the war. The Secret Intelligence Service had grown rapidly, recruiting officers from the military, from universities, from resistance movements and escape networks. Vetting procedures, though rigorous by the standards of the time, could not examine inner convictions of every candidate. They could check records, interview associates, look for evidence of Communist affiliation. They could not see into the mind of a man who had undergone conversion in captivity, or who had calculated that his best chance of survival lay in cooperation with captors.

The ideological fracture the Cold War produced also created opportunities for intelligence services on both sides. The Soviet Union recruited Westerners disillusioned with capitalism, who had embraced Communism during the war or in its aftermath, or who saw in the Eastern bloc an alternative to the political order that had produced Depression and war. Western services recruited Easterners who had experienced Soviet domination and sought to oppose it. The traffic went both ways. Blake was one of the Westerners who moved in the direction the majority did not. His movement was unusual but not unique. Cold War intelligence history is filled with such crossings.

The Joint Services School for Linguists, where Blake had studied Russian, was itself a product of post-war expansion. The school trained hundreds of officers in languages the services needed. Graduates went on to serve in stations around the world, handling intelligence requiring linguistic expertise. The school was a pipeline, feeding trained personnel into the intelligence apparatus. Blake had passed through that pipeline. His presence demonstrated the system’s success in producing qualified officers. His later betrayal demonstrated the system’s inability to guarantee their loyalty.

The Berlin station, where Blake was posted, was a microcosm of the larger intelligence environment. It housed officers from multiple services, conducted operations against multiple targets, coordinated with allies on joint projects. The tunnel operation, later designated Operation Gold by Americans and Operation Stopwatch by the British, was the most ambitious of these joint projects. It required cooperation, trust, sharing of information between services that had not always worked well together. Success depended on secrecy of planning and integrity of participants.

Blake’s presence introduced a variable neither service had anticipated. The KGB now had access to information about the operation through an officer part of the planning process. The degree of access depended on his clearance level, his assignments, information flowing through his hands. The documents do not provide complete accounting of what he knew and when he knew it. But the general outline is clear: Blake was in Berlin, the tunnel was being planned, and the Soviets had a man inside.

The paradox Blake’s presence created would only become fully apparent later. The tunnel, when completed, would produce vast quantities of intelligence. Recordings would capture hundreds of thousands of conversations, providing insights into Soviet military operations, political deliberations, internal disputes. The operation would be hailed as a technical triumph, demonstration of what Western intelligence could achieve through audacity and engineering. But the intelligence the tunnel produced would always be shadowed by the question of what the Soviets had allowed to be heard.

The KGB’s decision to keep Blake in place rather than exposing him immediately suggested it valued him as a long-term asset. A later account, published in 2019, argued that the Soviets “valued Blake so much, they feared his exposure more than they feared a breach of their secrets.” Over nine years of work for Soviet intelligence, Blake passed thousands of documents to handlers. His information compromised operations, exposed agents, and damaged services that had trusted him. The tunnel was one part of a larger picture, but significant. The operation’s success depended on secrecy, and secrecy was already broken before the first shovel went into the ground. According to that 2019 account, the Soviets decided not to ‘discover’ the tunnel until April 21, 1956, in order to protect Blake from exposure.

Some historians have argued that the tunnel represented a genuine intelligence achievement, its value only later compromised when Blake’s betrayal became known. According to this reading, Moscow’s primary motive in allowing the tunnel to operate was shielding their source, not conducting an elaborate deception campaign. The intelligence the West gathered was authentic in substantial measure, and the Soviets could not entirely control what passed through the cables. They could have shut down the tunnel at any time by staging its discovery, but they waited because exposing it prematurely would have revealed advance knowledge, pointing toward a mole. The decision was defensive: preserve Blake, accept some intelligence loss, control what could be controlled.

Both readings may capture part of the truth. The Soviets certainly had incentive to protect Blake, and the tunnel’s discovery in April 1956—nearly a year after operations began—was staged to conceal the source of their knowledge. But the Soviets also had opportunity to use the tunnel as a channel for disinformation. If they knew what the West was listening to, they could ensure certain conversations took place, certain information was shared, certain impressions created. The question of what was real and what was planted would hang over intelligence the tunnel produced.

Blake’s arrival in Berlin placed him at the intersection of these possibilities. He was a case officer in a station planning the most ambitious technical operation of the Cold War. He was a Soviet agent recruited in captivity who had concealed his allegiance through vetting, debriefing, social rituals of the service. He was, in intelligence terminology, a mole: an asset embedded within an adversary’s organization, waiting to be activated, passing information to handlers, maintaining cover that allowed him to operate.

The documents recording his posting offered no hint of what he had become. The posting order was paper, typed and filed. The station roster was a list of names. The personnel file was a collection of records tracing a career but unable to penetrate a conscience. The system producing documents was designed to manage personnel, not detect betrayal. It assumed officers it processed were what their files said they were. Blake’s file said he was a loyal officer with distinguished record. The reality was otherwise.

The Berlin station, in months after Blake’s arrival, continued preparations. Tunnel planning advanced through meetings, memoranda, technical assessments. The Americans, led by William King Harvey, pushed the project forward with energy that had become his hallmark. Harvey had transferred to the CIA from the FBI in 1947 and built reputation as aggressive operator pursuing targets with single-minded determination. The tunnel was his project as much as anyone’s, and he drove it toward execution.

The British, led by Peter Lunn, contributed experience from Vienna and knowledge of Berlin’s terrain and infrastructure. Lunn had run Operation Silver and understood possibilities and limitations of tunnel operations. His presence in Berlin, and his role in planning, gave the British stake in outcome. The collaboration negotiated in London was now implemented on the ground.

Blake stood within this collaboration, unknown to those who welcomed him as colleague. The station held meetings, discussed operations, shared information among officers supposed to trust one another. The trust making collaboration possible was the same trust making betrayal possible. The system assumed loyalty because it had no reliable way to detect disloyalty. Vetting process, background checks, personal references all pointed toward Blake’s reliability. The reality he had constructed during and after captivity pointed elsewhere.

The irony of Blake’s position would only emerge later, when betrayal became known and consequences became clear. At the time, he was simply a case officer doing his job. He handled agents, processed intelligence, participated in routines of station life. The tunnel was one operation among many, its significance not yet apparent. Recordings that would fill thousands of reels had not begun. Conversations that would later be analyzed and debated had not yet taken place. The operation was still in planning stages, outcome uncertain.

Planning documents crossing desks of officers in London and Berlin did not mention Blake except as a name on a roster. Formal authorizations later required—signatures from senior officials, approvals from political leaders—were still in the future. The operation existed in realm of proposals and assessments, not yet in realm of executed actions. But presence of a Soviet agent within the station meant the proposal was already compromised. The Soviets knew what was being planned, and they could decide how to respond.

The systemic vulnerability Blake represented was not unique to the Secret Intelligence Service. American services had their own moles, their own cases of betrayal, their own failures of vetting. The Cold War created pressures straining ability of any service to guarantee loyalty of personnel. Ideological stakes were high, and attractions of opposing side were real for those disillusioned with their own. Blake was one instance of broader phenomenon, but his particular position—inside Berlin station, during tunnel planning—gave his betrayal specific significance.

Documents surviving from this period do not reveal what Blake told handlers about the tunnel. Soviet archives that might contain such records have not been fully opened, and KGB internal histories remain classified. Blake’s own account, given after arrest and conviction in 1961, provided some details but could not be independently verified. Gaps in record mean certain questions remain unanswered: exactly what he passed, exactly when, exactly how Soviets used information.

What documents establish is sequence: Blake posted to Berlin, tunnel planned, Soviets had advance knowledge. Causal chain runs from his recruitment in Korea through return to service, posting to Berlin, presence in station during planning phase. Institutional decisions placing him there—needs of service, expansion of Berlin station, demand for Russian speakers—created conditions for compromise. The service did not know what it had done. It had placed a mole in the garden, and the garden was about to become site of its most ambitious operation.

The posting order that had brought Blake to Berlin was now a document in a file, its purpose served, its significance concealed. The station roster listed his name alongside names of other officers, all presumed loyal, all trusted. Planning meetings continued, memoranda circulated, preparations advanced. Blake stood in the doorway of the Berlin station, a man with a posting order in his file and a secret that would shape everything that followed.