In the Enemy’s House:
Venona and the Maturation of American Counterintelligence 
Presented at the
2005 Symposium on Cryptologic History
John F. Fox, Jr., FBI Historian
One man was tall, thin, a genius linguist at the NSA who was working on breaking coded telegrams sent from Soviet offices in the US to Moscow.  The other was a lawyer and cop, a young FBI supervisor recently transferred to Headquarters. A relationship did not blossom immediately and neither man knew what, if anything, to expect from the other. Some might predict that men from such diverse institutional cultures would be incompatible. And yet within weeks, a working relationship and, thereafter, a friendship grew between the NSA's Merideth Gardner and FBI Special Agent Lamphere. Lamphere later described this success saying:
"I stood in the vestibule of the enemy's house, having entered by stealth. I held in my hand a set of keys ...and we were determined to use them. 
FBI Counterintelligence Before Venona
Although the origins of the FBI's counterintelligence responsibilities are to be found at its birth in 1908, the FBI's permanent emergence as a key part of America's intelligence community began the mid-1930's. As war broke out in Europe in 1939, the FBI received official confirmation of its role in counterintelligence in cooperation with ONI and MID. In June 1940, Roosevelt even tasked the Bureau with responsibility for foreign intelligence in the western hemisphere. From the entry of the US into the war in 1941, the FBI, with cooperation of its fellow agencies and significant foreign allies, effectively negated Axis intelligence operations in the US and the western hemisphere.
The Bureau was distinctly less successful in identifying the Soviet threat during the same period. Many young leftists in the early 1930's had entered the government in the early throes of the New Deal and embraced a Communist siren under whose call significant numbers of them were willing to pass along valuable information to the Soviet Union during the war. A general leftist tilt in the government meant that these ideologues blended well into the Washington bureaucracy while keeping their strong Soviet sympathies largely hidden. The tradecraft of Soviet intelligence personnel, the well honed Communist Party tradition of conspiracy, and a lack of concern in the Roosevelt administration towards Soviet spying meant that little of this growing Soviet intelligence web was found except by accident in the opening years of the war.
But by 1943 the FBI was beginning to sense the outlines of the Soviet effort. Surveillance of Communist functionary Steve Nelson revealed the infiltration of the Manhattan project and alerted the FBI to the role that Soviet diplomats played in gathering intelligence information sparking the COMRAP or Comintern Apparatus Case. A number of Communist Infiltration or COMINFIL investigations into communist penetration of specific industries were launched. Another tantalizing set of clues to Soviet intelligence emerged in the ALTO Case, where the Bureau intercepted coded messages passed from Soviet agents in Mexico to a mail drop in the United States run by a Lydia Altschuler for whom the case was named. The messages' book code was unreadable until several years later when Venona mentioned what book to use and the Bureau learned that these messages concerned Soviet attempts to free Trotsky's assassin. Nor were these the only significant investigations conducted in the last years of WWII. Still, the Bureau's investigations revealed few spies in real time and the scope of Soviet intelligence operations in the United States remained hidden.
This situation did not last. Two and half weeks after President Truman declared victory, Soviet code clerk Igor Guzenko defected to the RCMP. Director Hoover declared the CORBY Case, as the RCMP investigation was known, to be the Bureau's top priority. On November 7th, Elizabeth Bentley visited the FBI's New York office and began to recount her role as a courier for two espionage rings in Washington, DC Continuing her confessions through the month, she named dozens of persons in the US who had given her information. She identified as Soviet agents persons in the White House, the State Department, the War Department, the OSS, and many other departments. And unknown to her, much of what she was saying fit in with what the Bureau knew from its other investigations. Bentley was connecting the dots found by the few Agents working Soviet FCI during the war. The GREGORY case, as the Bentley inspired investigation was called, immediately became a much greater priority than Corby.
Initially the Bureau tried to use Bentley as a double agent. However, it was immediately clear that the Soviets were done with her. Worse, many of her numerous contacts had been put on ice following Guzenko's defection and so even as the FBI initiated widespread surveillance of those named by her, there was little actual espionage being conducted that the Bureau could discover.
By January 1947, investigation into Bentley's leads had reached a dead end and the Bureau debated what to do. Analysis of the many Gregory-related files across the Bureau's organization showed that the likely result of bringing any case to trial would result in "an acquittal under very embarrassing circumstances." 
Bentley had come with a wealth of knowledge, but little else. That did not mean that the Bentley case was a failure. 27 government employees had been identified by Bentley as Soviet agents and 21 non-government employees. The case had led the Bureau to nine subjects about whom it had previously not had any information, one of whom worked in the government. And it provided strong corroboration of the bona fides of Whittaker Chambers and confirmation of earlier Bureau investigative conclusions.
In the end, a case summary was turned over to the Department of Justice for consideration of whether or not to prosecute.  Within days, a senior Justice Department official had leaked information about the case to the press, destroying any chance to continue it as a counterintelligence investigation. The Bureau was furious. Attorney General Clark told the Bureau that he knew who the leaker was and that the problem would not repeat itself; it did, but that problem is for another paper. Clark then asked the Bureau which of three approaches should be taken with the case: 1) continue it as an intelligence operation; 2) openly interrogate a select number of principles; or 3) furnish individual departments with evidence of the conspiracy sufficient to dismiss those Soviet agents still in federal employ?
Hoover assigned the matter to his Executive Conference, but didn't think much would come of the case. The Conference agreed. The case could no longer be continued as an intelligence investigation as all of the subjects were "very security conscious." Furthermore, due to publicity, the effective interrogation of select principles had been compromised by the leaks. Prosecuting the matter successfully was also unlikely.
In the end, the AG decided to have the Bureau interview the principals with the hope that better evidence could be developed. Even before the Bureau followed through on the AG's orders, the effects of the Bureau's investigation and the subsequent leaks to the press began having an impact. In February, Alger Hiss left the Federal government for the Carnegie foundation and the next month Harry Dexter White left the International Monetary Fund. By mid-April, the FBI had conducted many of the interviews of targets in the Gregory Case, most of them on the same day, but "no material admissions were obtained" from the subjects and by the end of spring, Justice had adopted a new tactic: the Federal grand jury of the Southern District of New York. In the end, this tactic won two convictions, Alger Hiss and William Remington, both for perjury.
While the grand jury began to call witnesses, significant changes were occurring in American intelligence. On July 26, President Truman signed the National Security Act creating the Central Intelligence Agency and an American Intelligence Community. Under this new law, domestic counterintelligence remained with the Bureau. Other aspects of intelligence work also remained outside of the new CIA, specifically the Army's cryptanalytic efforts. One of these efforts, Venona, had begun several years earlier, but it is with what happened at the beginning of September that we are concerned.
The Bureau Learns About Venona
It was on September 1, that the FBI's liaison to the NSA, Special Agent S. Wesley Reynolds, was briefed by Colonel Carter Clarke on the breaks in Soviet diplomatic messages. Clarke asked Reynolds if the Bureau knew of any Soviet covernames that might help his team's effort. Reynolds soon turned over a list of 200 known covernames that the FBI had acquired. Most of them had not been found in the traffic to that point. From NSA, the FBI received the fragmentary decrypts produced so far. Reynolds turned them over to the Espionage Section of the Security Division, and the message fragments were placed in a safe and forgotten. 
Several months later a new supervisor, Robert Lamphere, took an interest in that safe with "several pieces of paper that had a special top-secret classification." Lamphere had joined the Bureau in September of 1941. After training he was assigned to the field and eventually to New York where the counterintelligence bug bit him. He worked several important cases there including investigations of Hede Massing and Gerhart Eisler. In September of 1947 he was transferred to Headquarters as a Supervisory Special Agent and placed in charge of counterintelligence coverage of countries satellite to the Soviet Union. By March of 1948, Lamphere was longing for a more active CI role and asked his Section Chief Pat Coyne if he could tackle the fragmentary decrypts that NSA had supplied to the Bureau. Coyne agreed and Reynolds arranged for Lamphere to meet with Frank Rowlett. Rowlett forcibly impressed on him the need for security in dealing with the fragmentary material and introduced him to NSA's Merideth Gardner. 
When they first met, Gardner was reserved and could not suggest how Lamphere might help him in his work. Lamphere suggested taking one of the messages and writing a memo on it based on FBI information. Gardner was noncommittal but Lamphere went ahead anyway. Every few weeks he would drop off a new memo and pick up any new decrypts. After a few exchanges, Gardner began to get an idea of the resources the FBI brought to the table and wondered if Lamphere could get the plain text of any Soviet messages sent from New York to Moscow. Lamphere called the New York office and received a surprisingly large response. Gardner was thrilled and NSA had soon made some major strides in applying this new material to the coded messages. 
The NSA's work began to have an impact on FBI investigations. On June 4, 1948, Under the signature of Security Division AD Mickey Ladd, Lamphere sent a Top Secret letter to the Washington Field Office relaying information about Max Elitcher, an engineer who was recruited for Julius Rosenberg's spy ring and later provided evidence against him.  Three lines describing the intelligence about Elitcher have not been released, but given the timing of the letter, Lamphere undoubtedly based the letter on the information found in Gardner's Special Report #6 of April 27th.  This report discussed, among other things, Soviet agent Antenna's interest in recruiting Elitcher. Gardner's report had covered more than just Elitcher, but its additional information on Antenna, Antenna's wife, Ethel, and others does not appear to have been disseminated at this time. Lamphere must have been using Elitcher as a test case to evaluate how to apply the Venona intelligence.
This first dissemination of Venona material shows something else about Bureau procedures. The intelligence in Lamphere's letter was attributed to a highly sensitive source, suggesting perhaps a live informant or surreptitious entry. This subterfuge was purposefully used to disseminate Venona material to offices in the Bureau whether the case Agent was indoctrinated into the program or not--and few were. When such intelligence was disseminated, the information always came with the caveat that no dissemination was to be made without Mr. Ladd's approval. The FBI disseminated this sanitized intelligence, still at the TS level, on occasion to the Attorney General and the White House, but in doing so kept the subterfuge that attributed the material to a live source. 
Within a week of the dissemination of the Elitcher information, the Washington office sought headquarters' permission to institute a technical surveillance on Elitcher "to determine if [he] is engaged in espionage or related activities on behalf of the Soviet Government..." per evidence cited in Headquarters' earlier letter. Headquarters, in turn, sought the Attorney General's permission for the surveillance, reporting the disguised information as Lamphere originally wrote it and the Washington Office parroted it. Such surveillance requests were routine and were handled by several people in the Bureau and DOJ. It is not surprising that such a sensitive source would not be named outright in the request, even one that remained Top Secret. Even so, there is nothing that suggests that Attorney General Tom Clarke was ever briefed on Venona even though he received intelligence from the program from time to time. The only evidence I found of the Bureau informing persons outside of the Bureau about the nature of this source during the period this paper covers was when Director Hoover briefed AG Brownell in 1953 about the intelligence regarding Ethel Rosenberg. 
As the Bureau's Elitcher investigation proceeded, further leads into Antenna's spy ring were being produced at NSA. On August 12, Gardner issued a special study based on a revised translation of the Antenna messages. Lamphere immediately put this intelligence into the Bureau investigative pipeline, directing the New York office to consolidate its investigation titled Joel Barr and UNSUB-"Unsub" in Buspeak meaning unknown subject. In the future, New York was to refer to the case only by the title Joel Barr-Espionage, R. No further reference to the unknown subject was to be made "for security reasons." 
An October 18 report from New York suggests why this order was made. The report noted that the UNSUB, with aliases ANTENNA/LIBERAL, was believed to have acted as an intermediary between a person and persons working on wartime nuclear fission and was connected to agents covernamed METR and NILS. Information then available about Antenna/Liberal appeared, at first, to be a possible match with Joel Barr, but it was not a certain one and the Bureau eventually rejected it. An important reason for this rejection concerned the bit of information about Antenna's wife, Ethel. This information clearly ruled out Barr who had no such spouse. 
Through the summer and fall of 1948, therefore, the FBI was making significant strides in exploiting NSA's breaks in the Venona traffic. At the same time, the issue of Soviet penetration was becoming a significant political issue that would greatly hamper the FBI's work, though not its relationship with NSA. President Truman had accepted the Democrat Party nomination that July, and within two weeks, the Republican-controlled Congress began hearings based on Soviet penetration of the US government. Elizabeth Bentley was called as a star witness and the dramatic charges, denials, and countercharges filled the hot days of August and September. These hearings emerged from the earlier leaks on Bentley, which had become a torrent by then, and the FBI had to maintain a wary and troubled relationship to the Committee's work, which was often informed by the memories of retired Agents. To the credit of the FBI and the NSA, no aspect of Venona appears to have been compromised through these hearings and through the grand jury investigation; this, of course, was a small victory as William Weisband and Kim Philby did their damage through other channels.
Given the significant results emerging and the hope of more breakthroughs, it is not surprising that on October 19, 1948, Lamphere and Reynolds of the FBI and Rowlett, Kirby, Gardner and Hayes of NSA, formalized the working relationship begun earlier that year. As Gardner later wrote: "by this time it was amply plain that the FBI was the logical recipient" of the Venona material. Bob Lamphere later described the significance of this period:
We were inside the enemy's house; men were coursing down the corridors, following the leads to which our keys had opened the doors. ...It was easy to envision that soon, very soon, there would be more keys available, more corridors to explore. I could look ahead and see us coming closer and closer... to spies who were actually still at work among us. 
This optimism, though, was in hindsight and no active spies had yet been identified. In fact, the pace of discovery appeared to slow down through the fall of that year.
The wider world, knowing nothing of Venona's successes, concentrated on the November presidential elections and the public battle over whether Hiss or Chambers was lying. The problem of Soviet penetration seemed to be a partisan battle with President Truman denouncing red herrings and the Republican Congress wondering if it was going to get burned from airing accusations about Alger Hiss and others who vociferously pronounced their innocence. Even the Justice Department was having second thoughts as it considered prosecuting Whittaker Chambers for perjury.
As the Bureau aided the federal grand jury that was investigating the Bentley leads and considering whether to indict Chambers or Hiss for perjury, it also followed any new leads that came from Gardner and his colleagues. NSA by this time had begun to make larger breaks in a series of messages dealing with an agent named Homer/Gomer, who had access to high level US/British diplomatic messages. At this time no identification could be made. The issue of whether Venona would lead to active spies remained a tantalizing mirage, though, and the work continued. It was frustrating for the FBI to devote tens of thousands of man hours to investigating people one reasonably knew were spies and yet not catch any of them in the act of committing espionage.
This state did not last through the New Year. On Friday, December 31st, Bob Lamphere returned from meeting with Gardner bearing some newly recovered traffic. One message, dated 1944, described a young woman with a communist background who was moving from New York to Washington to work for the Justice Department. In the message, the KGB reported that it wanted permission to recruit her. Her codename was to be SIMA. Lamphere thought this SIMA might still be active and immediately informed his supervisor, Howard Fletcher, then Number 1 Man in the Espionage Section. Fletcher told Lamphere to wait right there, left his office, and returned a half hour later. The only possible match for SIMA, he reported, was Judith Coplon, an analyst still working in the Department's Foreign Agent Registration Office. She had access to FBI documents. 
Holiday forgotten, the FBI immediately worked the SIMA/Coplon case, investigating her background, her access at Justice to FBI records and other sensitive material, and her contacts in and out of the office. Physical and technical surveillance quickly revealed that she was likely an active spy and, given her access to classified material, something had to be done immediately. Since much of her access came from temporary duties she had volunteered for, Coplon was asked to devote her full time to her regular position. Unaware that she had been identified, Coplon maneuvered to continue her access to FBI material.
Given her role in Justice and closeness to the Bureau, the FBI appears to have rejected the option of doubling her and so needed to catch her in the act of spying in order to have a chance to arrest her. Lamphere drew up a dummy FBI report on Amtorg that suggested that the company's attorney, Isidore Needleman, was an FBI source. Coplon's supervisor ensured that she would have access to it and she readily took the bait. When, FBI wiretaps revealed her travel plans to travel to New York City in order to pass what she had collected to her control, the Bureau was ready. From a legal point of view there were a number of pitfalls in this. AAG Peyton Ford told the Bureau that there wasn't enough evidence for a warrant, but that Coplon could be arrested if she was seen giving something that looked like a document to someone else or if the Agents surveilling her had probable cause to think a crime had occurred. The FBI thought this was sufficient and planned to be in a position to make such determinations.
On March 3, 1949, having folded her information carefully into small packages and wrapped them in lingerie, Coplon left for her rendezvous. Bureau Agents followed her to New York where, after extensive maneuvers to detect any surveillance, she met with Valentin Gubitchev, a Soviet national working for the UN. The surveillance was detected and no hand-off of Coplon's material occurred. Instead, the Bureau arrested the pair and seized Coplon's handbag full of information gleaned from FBI materials.
By April 25th, the trial had begun. The US Attorney prosecuting it planned for a short trial; it lasted well into the summer. With luck and bluster and an uncanny knack to embarrass the prosecution, Coplon's over-the-top attorney Archie Palmer overwhelmed the elderly Judge Reeve and the trial descended into farce. On June 1, 1949, Palmer demanded access to all of the data slips Coplon had hidden in her purse, not just those entered into evidence by the prosecution, and then he also demanded the FBI reports on which they were based. Without a legal basis to stop graymail, Judge Reeves decided that there was no national security reason to withhold the material; at worst, he thought, the release would only endanger "individual lives". Palmer then demanded the FBI files on which the slips had been based; Reeves agreed. 
Director Hoover was furious as he had strongly opposed the release of the additional data slips and, especially the release of the reports behind them. He had argued that the case should be dropped rather than reveal the FBI materials behind them. And he was right. The press had a field day as the reports, which Palmer insisted should be read into the record, revealed a number of things including FBI surveillance of Soviet nationals at the UN, FBI interest in a number of Hollywood leftists who had communist contacts, and other content from the FBI's files unfairly categorized by the media as a farrago of gossip and unverified rumor. Perhaps we could say the FBI was lucky in that it had avoided a more serious issue. Palmer had not explored the predicate to the FBI's investigation. Had he done so, the security of Venona would have been seriously threatened and even the disclosure that Justice would give up the case rather than compromise the source would have focused attention on that undefined predicate. That Palmer did not raise the issue was the only luck the Bureau had in the trial.
In the end, Coplon was found guilty on two counts. Sentencing was held in abeyance and her bail increased as she was to be tried in New York with Gubitchev later that year. That trial too had its fireworks as FBI wiretaps were exposed and the communist press demanded independent investigations into so-called government illegalities. Coplon, though, was again found guilty. On appeal, the verdict was overturned and she was allowed to go free. The indictment was not dismissed as, according to the appeals judge, the evidence against her was overwhelming. Coplon never served jail time for her crimes.
In the aftermath of this fiasco, the first public reference to Venona derived intelligence was made. In a September 1951 article on the case for True Detective magazine, a writer clearly described the FBI's predicate as a sensitive source that suggested Coplon was being recruited for espionage. Inquiry by the Bureau showed that the leak came from Justice. Fortunately, because attorneys at Justice only knew the sanitized form of the intelligence, its true source was not compromised.
Throughout this period, the FBI's work on Venona-related matters expanded and Lamphere came to head a team of supervisors dedicated to overseeing all Venona-derived investigations across the Bureau. At the same time, these investigations were even branching out internationally. Having met with Carter Clarke on April 4, British intelligence representatives met with Lamphere and other FBI Agents working the Venona material. The British were interested in the Bureau's work on the covernames, especially any work on an agent named REST who was clearly connected to the British role in the Manhattan Engineering District [MED] Project. 
The FBI had little on Rest at the time as the information "was very fragmentary...not having been completed to any extent..." by NSA. By August 1949, though, the Bureau had identified a document concerning atomic research that Rest had provided to the Soviets in 1944. Turning to the Atomic Energy Commission, the AEC, the FBI asked for access to the original document and learned that it had been written by Klaus Fuchs, a member of the British delegation to the Manhattan Engineering District project. A review of FBI files showed that Fuch's name had come up earlier in the CORBY case when the RCMP found it in an address book of Israel Halprin, a college professor Guzenko had identified as a Soviet agent. Fuchs was looking like a good candidate for REST. 
With these breaks in understanding the REST message, the Bureau reappraised its earlier information and instituted full investigations of Fuchs and his sister, Kristel Heineman. Additional information from a foreign source suggested four possible matches for Rest, Fuchs again being one of them. At the same time, the Bureau conducted additional investigation into identifying GUS/GOOSE who was connected to Rest. By October 29th, the Bureau was formally notified that the British Government was convinced that Fuchs was REST.
Like the subjects of the Gregory Case, though, there was not enough evidence to convict Fuchs and so the British proposed to notify his employer that he presented a grave security risk and to call Fuchs in for extensive interviews. They wanted US permission, though, before they did so. The FBI thought this appropriate and hoped that a Fuchs interview would help to identify GOOSE and others connected to Fuchs's espionage. Beginning on February 2, 1950, Fuchs was interviewed several times by the British.
In a related matter, two weeks after the first interview, Bob Lamphere opened an investigation on Kalibr, the husband of OSA and a contact of Antenna/Liberal. Ironically, this occurred almost simultaneously with Joseph McCarthy's Lincoln Day speech to a Republican ladies' group in Wheeling, West Virginia. While McCarthy railed and the FBI investigated the British continued to interview Fuchs.
By the third interview with British intelligence, Fuchs had admitted to espionage from the end of 1941 to February of 1949. His admission provided the British government with the leverage it needed to charge him with a crime. Knowing the British were soon to publicly try Fuchs, the Bureau rushed to wrap up the loose ends to its REST investigation. Fletcher, in a memo to Ladd, asked for permission to interview Fuchs's sister before news of her brother's prosecution got out. Permission was granted and the interview was held that day. Meanwhile, the Bureau began to press the British to get answers to US questions about Fuchs's activities in Canada and the US.
As a quick aside, it should be noted that it was in this period that Ted Hall was identified as the Soviet agent with the covername MLAD. Soon, the FBI began considering whether or not Hall was the soldier named SCHMEL whom Gold had visited in New Mexico. With the identification of Greenglass as that soldier, it was clear that Hall was not SCHMEL. Although investigation into Hall continued, he had already decided to become more of a public activist, leaving his underground work, and his control had already fled the country. Like the Gregory subjects, the Bureau had no opportunity to catch Hall actively engaged in espionage work and so could never prosecute him. 
Wisely, the Bureau did not look to prosecution as the only, or most important, factor in an FCI investigation. Director Hoover told a House Committee in February 1950 that counter-espionage requires "an objective different from the handling of criminal cases." It is more important is to ascertain his contacts, his objectives, his sources of information and his methods of communication" as "arrest and public disclosure are steps to be taken only as a matter of last resort." He concluded that "we can be secure only when we have a full knowledge of the operations of an espionage network, because then we are in a position to render their efforts ineffective."  Clearly, FBI counterintelligence policy was maturing rapidly as it pursued Fuchs's contacts.
Even as the FBI was getting ready to interview Fuchs, it was evaluating how it should handle the Venona materials and leads developed from them. In a May 15, 1950, memo from Alan Belmont, head of the Espionage Section, to Mickey Ladd, the Assistant Director of Division 5, Belmont presented a brief summary of investigative developments through the Venona traffic. The Summary, written by Lamphere, noted that to date, the traffic had provided "certain fairly detailed information" regarding Soviet espionage during the period of April 1944 through March of 1945. Breaking the information down by major investigations, Belmont related how Venona had given good intelligence on the Silvermaster and Altschuler networks, had given important corroboration to information learned in the MOCASE, and had set the Bureau on the trail of a number of other Soviet agents including Kalibr (who would be identified within weeks of this memo), Ted Hall and Saville Sax, Judith Coplon, Klaus Fuchs, Soviet agents close to former VP Wallace, and others. 
Belmont further noted that the file dealing with the Venona information was being used as a control file to insure that the individual cases growing out of the information from the NSA were promptly and vigorously handled. Hoover enthusiastically noted that it was "very important to press all angles. Please bring this memo up to date from time to time for my information."
Lastly, Belmont commented on the Bureau's tentative identification of Alger Hiss as ALES, a clear reference to March 1945 message number 1822 in the Washington to Moscow traffic. Belmont said that an agent, cover-named ALES, was a leader of a small group of spies who were mostly relatives, worked in the State Department and gathered intelligence on military issues. Why Hiss is connected with this message is unsurprising. Each of these clues as well as the mention of ALES's connection to the Yalta Conference and a trip to Moscow afterwards each fits what was known about Hiss. Hiss, of course, had been convicted of perjury less than six months before, and would have immediately occurred to Lamphere's team which had worked many aspects of the Silvermaster case during the previous years. Still, the conclusion was not certain. Belmont noted, "an attempt is being made by analysis of the available information to verify this identification."
While the Lamphere's team considered the ALES information, more important successes were made because the British finally allowed Bureau access to Klaus Fuchs. In May of 1950, the diplomatic niceties between the British Home Office and the US State Department had been conducted and the FBI was allowed to send Hugh Clegg and Bob Lamphere to England to talk to Fuchs. Under Lamphere's questioning on May 22, Fuchs positively identified Harry Gold as his contact in the United States. Clegg immediately cabled Washington and Gold was confronted that day. With this, according to Lamphere, "we had cases breaking everywhere" and over the next few weeks, Lamphere worked up to twenty-two hours a day as information "piled up from across the country" on leads from Gold and Fuchs. Most significantly, Fuchs's information unraveled the two-year-old Antenna mystery.
When the Bureau questioned Gold, he said that a contact of his was a man named Greenglass. Greenglass was immediately brought into the New York Office for questioning and it as immediately clear that he was a significant catch. His confession that day was so important that just after midnight on the 16th ASAC Whelan telephoned Security Division Inspector Alan Belmont about Greenglass's interview and two hours later, SA McAndrews called Headquarters to report that New York would be sending out a teletype based on Greenglass's information. The purpose of the warning was to ensure that the message was routed properly, in this case, not simply to the Security Division, but specifically to Bob Lamphere because of the impact it would have on his team's work. 
New York transmitted the message at 4:53 a.m. Although based on Greenglass's information, it was titled UNSUB, with aliases Antenna/Liberal. Greenglass had allowed New York to connect many of the pieces in the ANTENNA puzzle. The teletype pointed out that the likely candidate for OSA was Ruth Greenglass; for Ethel--Ethel Rosenberg; for SCHMEL-Greenglass; and for LIBERAL--Julius Rosenberg. 
Just after 8:00 a.m., Agents knocked on the door of Julius Rosenberg and asked him into the New York Office for questioning. Rosenberg did not give up any information and eventually left the New York office to meet with an attorney. Because of Greenglass's confession and cooperation, Julius was soon arrested for espionage and a month later, the FBI arrested his wife, Ethel, too. The trial and related matters have been well told by Radosh and Milton and so I won't go into them here, but it should be noted that because Julius was identified by a live person, most of the pitfalls of the Coplon trial could not be repeated. The FBI had learned to develop a criminal case separate from its intelligence work and so avoided the compromise of either one. 
In the six years following World War II, the Bureau had moved from having a shadowy perception of the Soviet intelligence threat to having a clear picture of the extent of Soviet penetration of the US government and the damage that its agents had done to America's interests. Venona had been vitally important to this change as Alan Belmont's 1951 update to his earlier summary showed. His memo noted that through Venona, the FBI had identified 108 persons involved in Soviet espionage, 64 of whom had been unknown to the FBI prior to the project. The memo also showed that the FBI had greatly expanded the detail about the Soviet networks broken with the help of Venona intelligence. The FBI now had a clear view of other Soviet intelligence operations in the US too, including its efforts against Trotsky and his followers, the White Russians, and US technical targets. And, according to the memo, the FBI's work on many of these cases continued in earnest. 
The FBI's security posture also improved. When the NSA in August of 1950 began compartmenting the Venona information under the codeword Bride and issued special instructions on the handling of such material, the FBI responded by issuing special handling and filing instructions for it and its Files Division created a Special File Room for this material and other source sensitive material that the FBI used. The Bureau also maintained its wariness in sharing intelligence with the Department of Justice, briefing the Attorney General on a need to know basis of course, but restricting the security information passed to lower levels of the Department.
With this vastly clearer image of the threat we faced, the FBI was able to move from a reactive counterintelligence policy to a proactive one, much like its successful effort against the Axis during WWII. By October 1951, the Bureau had initiated a program of intensive coverage of Soviet and Satellite personnel and establishments to thwart Soviet intelligence efforts and those by its allies. Although most of the details of this effort have not been released, it is clear from what is publicly available that this program included intensive electronic surveillance, a long-term effort to develop double agents within hostile intelligence establishments, and an effort to develop other double agents to flush out hostile intelligence personnel.
A 1955 briefing paper for Director Hoover released in the O and C files suggests success in this effort only four years after its initiation. This paper notes that the intensification program had successfully targeted cryptographic materials and penetrated the residences of foreign intelligence personnel. The memo gives eight examples, all of which are withheld, but the number alone suggests achievement. Surveillance, the report adds, also helped to identify a number of American walk-ins to the diplomatic establishments with hostile intelligence services. Upon investigation a number of these walk-ins were determined to have access to classified material. Finally, an intensive program to develop double agents was initiated in order to further Bureau intelligence goals. The 1955 paper cites at least five active double agents run by the FBI as well as several other agents turned over to other agencies to be run overseas. 
In short, Venona enabled the Bureau to take a long term approach to counterintelligence designed to develop intelligence about the intentions, activities and personnel engaged in intelligence work in order identify, penetrate, and neutralize these intelligence threats. Counterintelligence, for sure, is not an easy discipline to master, but the Bureau had done so and Venona played a key role in this maturation.
 The interpretations and conclusions presented in this paper are those of the author and may not be the official position of the Federal Bureau of Investigation.
I would like to thank Bob Heibel of Mercyhurst College for access to his Intelligence History program's important effort to turn each of the released messages into a fully searchable Microsoft Word document. It greatly aided me in trying to put this paper together. Second, I would like to thank John Haynes. When I began this paper, he was the one to suggest that I talk about how the FBI got into Venona, how the FBI used Venona in specific cases, and how the Bureau disseminated the material. These suggestions have informed this paper from the beginning and I regret that I cannot do justice to them here as a comprehensive story of the FBI's use of this intelligence requires at least a book length monograph.
 A quick aside on terminology. I will use the terms Venona, NSA, and KGB throughout despite their being anachronistic.
 Robert J. Lamphere with Tom Schactman. The FBI-KGB War: a Special Agent's Story. [New York: Random House, 1986.]
 65-56402-3856, 1/16/1947, Memo, Jones to Ladd.
 Robert Benson and Michael Warner, Venona: Soviet Espionage and the American Response, 1939-1957, [Washington, D.C.: National Security Office, 1996], p.xxii
 Lamphere, p.81.
 Lamphere, p.82.
 101-21157-7, Memo, 6/14/1948, WFO to HQ, Recommendation for Installation of Technical Surveillance.
 Gardner's "Special Reports" may be found at the NSA's web site under released materials. These reports and the Venona documents are organized by date of issue.
 65-58236, Memo, Ladd to Director, 1/8/1953, re Julius Rosenberg, Ethel Rosenberg, Espionage-R.
 65-53826-16, Memo, Director to NY, 8/18/1949.
 65-43826-3, Report, NY, 10/18/1948. Lamphere notes that this piece of information was not redacted when release of this report was made in the 1970's. See p.2 of this report.
 Lamphere, p.97.
 Lamphere, pp.97 to 98.
 Thomas and Marcia Mitchell, The Spy Who Seduced America: The Judith Coplon Story, [Mont Pelier, VT: Invisible Cities Press, 2004], pp.104 ff.
 65-58805-7, Memo, Fletcher to Ladd, 9/22/2005 and 65-58805-1202.
 Benson and Warner, xxvi.
 J. Edgar Hoover, Testimony before House Appropriations Committee, 2/7/1950
 This document may be found on the FBI web site's electronic reading room under the title "Venona." It consists of documents released to Senator Moynihan under the Freedom of Information Act.
 65-58236-50, Memo, Cox to Belmont, 6/16/1950.
 65-53826-80, TT, NY to Director, 6/16/1950.
 Ronald Radosh and Joyce Milton, The Rosenberg File, Second Edition, [New Haven: Yale University Press, 1997].
 This memo may also be found in the Venona material released to Senator Moynihan that is posted on the FBI web site.
 J. Edgar Hoover Official and Confidential Files, #149, "U. S. Foreign Intelligence Activities - Brief for Use of Director in Appearance before the Presidential Board to Review Periodically U.S. Foreign Intelligence Activities."