It was known in intelligence lore as “Black Friday.”
Since 1943, the United States had been intercepting and decrypting secret Soviet radio communications, compiling a surprisingly comprehensive view of the USSR’s military capabilities and intentions. Painstaking work by codebreakers at the U.S. Army Security Agency headquarters at Arlington Hall in Virginia near the Pentagon was producing uniquely valuable intelligence. The secret program, code-named VENONA, would eventually help expose some of the Soviets’ most dangerous spies, including the physicist Klaus Fuchs, who was passing American atomic secrets to Moscow, and the British diplomat Donald Maclean, the first member of the later notorious Cambridge spy ring to fall under suspicion.
But in late October 1948, almost overnight and without warning, the Soviets began changing their cryptographic systems, leaving the U.S. codebreakers in the cold. One by one, in rapid succession, each of the cipher systems went dark. At the same time, just as mysteriously, Soviet military, intelligence, and diplomatic headquarters in Germany and Austria stopped using ultrahigh frequency (UHF) radio to communicate with Moscow, shifting instead to landlines, depriving the West of a valuable stream of intercepts.
U.S. intelligence spent months trying to learn what had gone wrong. Navy investigators decided it was simply a routine systems upgrade by the Soviets, but others were not so sure. Only later would the Americans learn that VENONA had been betrayed by two Soviet spies. The first was William Weisband, a gregarious and well-liked Russian-language linguist at Arlington Hall. Born in Egypt to Russian parents, Weisband had emigrated to the United States in the 1920s and was recruited by the KGB in 1934. Making the office rounds and chatting with coworkers, he had learned of the Western success in breaking the codes. And Harold “Kim” Philby, the SIS liaison in Washington, had likewise been recruited by the KGB while a student at Cambridge in the 1930s. Conveniently for the Soviets, he’d been assigned to work with the Americans on VENONA. Based on the warnings of one or likely both spies, Moscow changed its ciphers and radio operating procedures.
By some estimates, Black Friday was the worst intelligence loss in U.S. history, leaving the West almost entirely in the dark about Moscow’s military capabilities and intentions.
The United States paid the most immediate consequences in Korea. The North Korean invasion of the south in June 1950 had been an intelligence disaster, with the failure to pick up even a hint of a war launched with the approval of Soviet leader Joseph Stalin setting off alarms in Washington and London. And not only had the Central Intelligence Agency missed the start of the war, but it had been wrong about the possibility of Chinese intervention, and wrong about North Korean capabilities.
The communist aggression in Korea was seen in Western capitals as a possible prelude to a similar attack on Western Europe by the enormous Red Army force that had not been withdrawn at the conclusion of World War II and still occupied eastern Germany and Poland. The brutality of the fighting in Asia and the surprising power shown by communist forces during the first year of the conflict only added to the fear that the United States and its allies were unprepared. Unsurprisingly, with Cold War tensions escalating and Washington deprived of the flow of valuable intelligence, pressure on the CIA to supply early warning of a Soviet attack “skyrocketed,” recalled Richard Helms, the future director of the agency, then serving as chief of operations for its clandestine service.
Thus far in its young history, the CIA was proving itself thoroughly outmatched by the formidable KGB. Since the creation of the Cheka during the Bolshevik Revolution in 1917, the Soviet secret police and intelligence organization had been known by many different names, but still relied on what founder Felix Dzerzhinsky called “organized terror” in pursuit of its aims.* The strengthening of the police state under Stalin made it next to impossible to recruit any spies in Russia. Getting an agent to report from inside the Kremlin “was as improbable as placing resident spies on the planet Mars,” complained Helms, a razor-sharp former wire service reporter who had served in Germany with the Office of Strategic Services, the World War II military intelligence agency that was a forerunner to the CIA.
In 1949, the CIA began parachuting Russians who had fled the USSR back into the country with the idea of establishing a network of agents to spy on military installations and the like. Almost all of the agents were arrested as soon as they landed, and of the few who did not disappear, most if not all were forced to serve as double agents by Soviet intelligence, meaning any information they sent was compromised.
Western intelligence therefore had to rely on outdated World War II information, details garnered from the censored Soviet press, and reports from occasional defectors. A small amount of signals intelligence—the collection and analysis of communications and electronic emissions—was trickling in from the first U.S. intercept stations being constructed around the Soviet Union’s perimeter. Other than rare overflights along the periphery of Soviet territory by U.S. and British military aircraft, there was none of the overhead imagery that the U-2 and satellites would later provide. “We were simply blind,” said David Murphy, a CIA officer who would serve in Berlin.
WASHINGTON, LONDON, AND BERLIN, 1951
The Berlin tunnel was born of this desperation.
The Berlin tunnel was born of this desperation.The CIA, created by the National Security Act of 1947 signed by President Harry Truman, had been given the task of centralizing and coordinating American intelligence. But its true mission was even more simply stated: “I don’t care what it does, all I want from them is twenty-four hours’ notice of a Soviet attack,” Secretary of State George C. Marshall famously declared. Given its performance, the chances of getting that warning did not seem promising.
Even before Korea, fear of Soviet aggression against the West had been escalating. Following the successful Soviet testing of atomic weapons in August 1949, a secret National Security Council report issued in April 1950, NSC-68, declared that the United States was “mortally challenged” by the Soviet Union and must intensify intelligence operations to get early warning of an attack.
If war came, Germany would be the main battleground and Berlin the likely flashpoint. The divided former German capital, deep in East German territory, was on the front line of the Cold War with the United States, Britain, France, and the Soviet Union each controlling their own zone in the city. It was the place where the Soviets and the Western Allies met most intimately—and uneasily.
Tensions in Berlin reached new heights in June 1948, when the Soviets blocked roads and rail lines leading to the Western sectors, expecting that they could force the United States and its allies to abandon the divided city. Instead, the West overcame the blockade with a magnificent airlift, flying in four thousand tons of coal, food, and other supplies daily for almost eleven months. Throughout the crisis, Washington feared that the Soviets might launch a war, but in the end, Stalin lifted the blockade in May 1949.
The North Korean invasion one year later was halfway around the globe, but it was seen by the CIA as an even more serious threat to Berlin than the blockade. “We considered it much more likely this time that the Soviets might move west,” said Peter Sichel, then chief of the CIA’s Berlin base.
Some three hundred thousand Red Army troops were positioned in eastern Germany. The United States, which had fewer than a hundred thousand troops in West Germany when the Korean War started, rushed over more forces and soon had a quarter million. But the Soviet bloc retained an overwhelming advantage among conventional forces. British intelligence calculated that the Soviets and their allies had 216 active divisions available for use in Europe, compared with 51 for NATO, the new Western alliance. Moreover, there was a danger that the Soviets would resort to a first nuclear strike because they assumed that the United States would use atomic weapons to stop the Red Army from overrunning Western Europe.
A CIA estimate in February 1951 concluded that the Soviets’ “ultimate aim” was to gain control over all of Germany and eliminate the presence of the Western powers in Berlin. If they were unable to meet these goals with political pressure, the agency reported, the Soviets might risk starting another world war. Knowing what the Soviets were up to in Berlin was thus a matter of the utmost importance, with millions of lives potentially at stake.
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Perhaps no one was more frustrated by the loss of Soviet radio traffic than a pipe-smoking and genteel Virginian named Frank Rowlett. Though unknown to the American public, Rowlett was an unsung hero of World War II and one of the nation’s top codebreakers. Mild-mannered and unpretentious, with rimless glasses on his round face, he looked like the high school math teacher he had once been back home in southwest Virginia. He had arrived in Washington in 1930 as one of the original three cryptanalysts hired for the newly created Army Signal Intelligence Service by the father of modern American cryptology, William Friedman. Rowlett had confessed to his wife that he did not have the slightest idea what a cryptanalyst did. But he proved to be an inspired choice, rising to help lead the VENONA project and playing a key role in designing SIGABA, the cipher machine credited with saving thousands of American lives during World War II by protecting U.S. military communications. He also led the team trying to crack the Japanese diplomatic code, dubbed PURPLE by the Americans. With tensions in the Pacific rising sharply, Japan had in 1939 introduced a highly sophisticated cipher machine for cable traffic between Tokyo and its embassies around the world. In September 1940, after eighteen months and untold hours of analysis, Rowlett’s team discovered a critical pattern of letters that led to breaking the code. “That’s it! That’s it!” the normally unflappable Rowlett cried, jumping up and down in excitement. He sent out for bottles of Coca-Cola for the whole team. Then they got back to work. Within two days, they were deciphering their first messages. It was a triumph of grinding work and true genius.
The intelligence derived from the decrypted Japanese cables was code-named MAGIC, and Rowlett and his team were considered magicians. The United States was able to read Tokyo’s messages to and from the Japanese ambassador in Berlin, providing crucial intelligence on both Japanese and German intentions. But the United States failed to mount a big enough effort to break the codes used by the Japanese army and navy—at heavy cost.
On December 3, 1941, Rowlett walked into his office at the Munitions Building in Washington and found a single-page translation of a PURPLE intercept from Tokyo to the Japanese embassy in Washington waiting on his desk. He was stunned to read that Tokyo had ordered the embassy to destroy its codebooks and cipher machines. He and a colleague concluded that the order meant Japan was preparing to go to war with the United States, and they quickly reported this up the chain of command. But with no matching intelligence about any Japanese military preparations or movements, the U.S. government did not anticipate the attack on Pearl Harbor.
A decade later, Rowlett feared the United States could face a new Pearl Harbor—this one with nuclear weapons. In 1951, he was serving as technical director of operations at the Armed Forces Security Agency, predecessor to the National Security Agency. Since VENONA, he had worked closely with Bill Harvey, a former FBI G-man who was then chief of the counterintelligence staff at the CIA. On the surface, the gruff and profane Harvey was as different from the courtly, soft-spoken Rowlett as could be imagined. Harvey, who drank martinis by the quart, referred to the coffee-eschewing Rowlett behind his back as “Our Father.” But the two quickly developed a mutual respect, as well as a shared sense of urgency on the need to fill in the gaps in American intelligence.
In early 1951, Rowlett and Harvey commiserated over the lost intelligence due to the Soviets’ Black Friday shift from radio to landlines. Perhaps they could figure out a way and place to attack Soviet landlines on a scale not previously considered necessary, or even possible.
Two cities were obvious targets: Vienna and Berlin. Since Soviet and Western forces jointly occupied both cities, there might be locations where the CIA could reach landlines used by the Red Army. But when the CIA began investigating Vienna in 1951, they discovered they were late to the game: British intelligence had been tapping Soviet cables through a system of small tunnels in and around Vienna for two years. Informing the Americans of this, the Brits magnanimously offered to share the take. The CIA was duly impressed with the intelligence collected about Soviet military capabilities and intentions, and rather than pursue its own project, it agreed to join the SIS operation. “There was too much at stake to risk any overlapping effort in such a narrow field,” recalled Helms. The British also suggested that “similar opportunities might be present in the Berlin area,” according to a CIA history. That possibility intrigued Harvey and Rowlett.
Berlin held potential for an operation on a far grander scale than Vienna. It was the central circuit for communications in Eastern Europe, the hub for an enormous network of lines dating from pre–World War I imperial days, stretching to Moscow. That role had been interrupted by World War II, but long-distance telephone and telegraph lines connecting the city to the rest of Europe had been restored in 1946. Still, the Americans and British were uncertain about how much Soviet forces actually used the cables, and what the intelligence value might be.
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In mid-1951, Staff D, the CIA’s new, highly secret office responsible for clandestine electronic surveillance targeting foreign communications, held exploratory talks in Washington about mounting an attack on Soviet landlines in East Germany, in particular Berlin.
Based on those discussions, the CIA base in Berlin was assigned to penetrate the East Berlin office of the East German Post and Telecommunications Ministry, which operated the telephone lines in Berlin. Neither Berlin base chief Peter Sichel nor his deputy Henry Hecksher were told anything about a tap or a tunnel—all they knew was that headquarters wanted information about the telephone cables.
Penetrating the ministry was not particularly difficult. Hecksher, a native German who had left Germany in the 1930s because of his Jewish background, had close contacts with Berlin authorities. It helped that the Berlin postal office had been one central entity before the occupation, so West Berlin postal officials had close working relationships with former colleagues on the other side, including some who supervised cables. Hecksher developed a network that brought in “reams” of material about the cable network, Sichel said.
The Soviets used two types of landlines in Germany: overhead lines strung on telephone poles, and buried cables. On the one hand, the overhead lines seemed an attractive target, as they carried the highest-level intelligence and military communications. But these special KGB-operated lines were guarded closely by roving patrols on the lookout for taps or other problems. The underground cables were likely a better target, since they were not visually inspected. If the CIA could place a tap, it might go undetected for some time.
The intelligence gathered from East German ministry sources showed that the underground cables in Berlin still followed the conduits created by the old German imperial system. Moreover, all Soviet telephone communications between Moscow, Warsaw, Budapest, Bucharest, and Vienna again went through Berlin. There was something else important, Sichel recalled: “Our intelligence brought to light the fact that these cables went close to the western border” in some locations.
Back at CIA headquarters in Washington, Helms was intrigued. The proximity of the cables in Berlin “suggested a long-shot possibility” of digging a tunnel to break into communications between Moscow and its military headquarters in Germany, Austria, Poland, and Hungary.
A long shot was more than enough for Harvey, who went to work laying the groundwork. He coordinated with Rowlett, who would soon join the CIA to take charge of Staff D. Discussion of the possible project was restricted to a very small group. Helms, despite his position high in the CIA’s hierarchy, assisted with the planning to keep the circle small. “I was, in effect, the action officer, and at times dealt with routine matters which in other operations would be the lot of an officer with a year’s experience under his belt,” he recalled.
To learn more about the Berlin cables, Staff D stationed an officer in Germany. Alan Conway, a seasoned former Army signals intelligence officer, operated from the Frankfurt headquarters independently of the CIA base in Berlin, in order to keep knowledge tight.
Lacking any engineering expertise, the team in Washington asked Gerald Fellon, a civil engineer in the CIA’s Office of Communications, to meet with Staff D to discuss a mysterious new project. Fellon, who had served with the Army during the war, was hardly an expert on tunnels—his entire experience was limited to several night shift visits to the Brooklyn–Battery Tunnel as a student civil engineer in 1948. But he knew more than anyone else at the agency.
It was a short meeting, Fellon recalled: “The only question they asked was whether a tunnel could be dug in secret.” He was told nothing about where this tunnel might be built, or why. Fellon replied rather vaguely that a tunnel could be built anywhere, though building one in secret would depend on the size. It would also take more time, and cost more money, he added, but it was possible.
That was the right answer. After the meeting, Fellon was transferred to Staff D and put to work on the project. He recalled, “Thus began planning for the construction of the Berlin Tunnel.”
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From the book BETRAYAL IN BERLIN: The True Story of the Cold War’s Most Audacious Espionage Operation by Steve Vogel. Copyright © 2019 by Steve Vogel. From Custom House, an imprint of HarperCollins Publishers. Reprinted by permission.
