In the final years of the Cold War and in the immediate post-Cold War period, US intelligence was faced with three serious cases of treason within its own ranks: those of the CIA officers Edward L. Howard, Aldrich Ames, and the FBI agent Robert Hanssen. In 1985, Howard fled to the Soviet Union where it is assumed he died from an accident several years later. Ames was arrested in February 1994 and is now serving a life sentence without parole. Hanssen was arrested in February 2001 and received a similar sentence. Both Ames and Hanssen, unbeknownst to each other, had offered their services to the KGB in the very year Howard defected to the USSR. The three men together betrayed a huge volume of US secrets to the KGB that had to do not only with the identities of human sources (agents) inside the Soviet establishment, including the KGB, but also with top secret technical programs of the FBI and the NSA. In several instances, Ames and Hanssen gave the KGB information about the identities of the same agents. Through Ames’ betrayal alone, about a dozen Russians, including several KGB officers, were executed for betraying secrets to the Americans. Some of the technical programs Hanssen gave to the KGB are still classified even today. This whole episode is well-known and has been discussed in many books and other sources.

The main thesis of Robert Baer’s book is that, apart from the three men mentioned earlier, there was a ‘Fourth Man’ (in capitals throughout the book) inside the CIA, who also passed secrets to the Russians from the mid-1980s onwards. This Fourth Man was never found; the book is an elaborate and very detailed analysis of the search for him, with many added observations and commentary from the author. Baer himself had a career with the CIA, though on the covert action side of the Agency and not in counterintelligence. In the mid-1990s in the Middle East, for instance, he was involved in attempts to overthrow the regime of Saddam Hussein in Iraq with the help of Iraqi exiles. He never took part in an investigation to root out traitors inside the CIA, which is what The Fourth Man is all about.

For this book, Baer has interviewed members of the small Special Investigations Unit (SIU) that was set up in late 1994, shortly after the arrest of Ames. It was mainly responsible for the hunt for the unknown fourth mole and consisted of three CIA officers and an FBI agent. One of the author’s main sources was the lead figure in the team, the CIA officer Laine Bannerman. He interviewed many of her colleagues as well, including the man suspected of being the Fourth Man. More about him later.

The idea that there was a Fourth Man is not entirely new. The late David Wise, a well-known intelligence expert who is the author of many books, discussed the hypothesis of a Fourth Man in an article in 2015.1 The argument in favour of the existence of a Fourth Man, both in the David Wise article and in the book by Baer discussed here, mainly centres on three Soviet intelligence officers (IOs) and their connection (or lack thereof) to the beginning of the Ames case in 1985. It was on 13 June 1985 that Ames made his so-called Big Dump in a meeting with the KGB in Washington. That’s when he gave the Russians the identities of all human sources he knew of that the Americans had inside the KGB and other sections of the Soviet establishment. The striking thing about these three Soviet IOs was that they had already been recalled unexpectedly to Moscow under false pretexts just a month earlier, in May 1985.

Of the three IOs who were recalled, two had been recruited by the CIA and one by the British Secret Intelligence Service (SIS, also known as MI6). Oleg Gordievsky had been recruited by the British in Copenhagen in the mid-1970s and was acting rezident (the Soviet equivalent of a CIA chief of station) of the KGB in London when he was recalled to Moscow. On his arrival, he was subjected to a harsh interrogation by the KGB, but he managed to keep silent about his true allegiance and was later exfiltrated from the USSR by MI6 in an operation that only succeeded through sheer luck and bravado.2 A GRU officer stationed in Athens smelled danger. He decided not go back to Moscow and escaped to the US. In the third case, a KGB officer stationed in Nigeria was recalled in May 1985. He went back and on arrival in Moscow was immediately arrested, subsequently tried, and executed.

The recall of these three IOs before Ames’ Big Dump is the major ‘anomaly’ among many discussed in The Fourth Man. It was looking for these anomalies that made up the work of the SIU to a large extent. Extremely detailed timelines were drawn up concerning who inside the CIA knew what and when about the many cases that had gone awry in the mid-1980s. However, there are always certain details of a case, minor and major ones, that defy easy explanation and could point to the existence of a traitor in the service. One reason such unexplained details are numerous is the fact that the opposing side, in this instance the KGB, obviously has no interest in cooperating and providing information that could explain the anomaly.

Take the case of the Soviet scientist Adolf Tolkachev, who was an important source for the CIA until his arrest by the KGB in mid-1985.3 It has generally been assumed that his arrest came as a consequence of Howard’s betrayal of him to the KGB in November 1984. But how then to explain the fact that Tolkachev told the CIA in the period before his arrest that the KGB was already investigating a leak at his research institute in April 1983? Often, there can be an innocent explanation for an anomaly. In the case of Ames, he could have betrayed Gordievsky and the two American assets before the Big Dump. He could then have lied about it to his debriefers after his arrest in 1994, or maybe his memory simply failed him.

In Baer’s view, the most plausible candidate for being the Fourth Man is the CIA official Paul Redmond, now retired, who ironically played a major role in the investigation that unmasked Aldrich Ames. SIU members and others Baer interviewed agreed with him on Redmond’s culpability, even though there is no real evidence that would hold up in a criminal trial, as there was when Ames and Hanssen had their days in court. What there is against Redmond is mostly circumstantial and often comes down to vague feelings of unease and suspicion. In other words, a real traitor other than Paul Redmond could easily still be lurking in the shadows somewhere. Redmond himself denies the accusations leveled against him, and even Baer is not fully certain about the identity of the Fourth Man, as he says repeatedly. Indeed, the author doesn’t even know ‘whether the Russians framed Redmond,’ he remarks in the epilogue.

Two more observations about the book are in order. The first is the highly confusing use of the term ‘double agent’ by Baer when he applies it to individuals such as Howard, Ames and Hansen. All three of them were Soviet agents, not double agents. Neither was the Fourth Man, if he exists, a double agent. A double agent is an individual who works as an agent for two services and is usually loyal to only one of them. That wouldn’t be the case with the Fourth Man.4 The origin of this confusion probably lies in the fact that Baer’s CIA career was not in counterintelligence and, as mentioned earlier, he was never involved in investigations such as the one discussed here. Secondly, the reference in the title to the US ‘overlooking Putin’ is misleading. There is barely a discussion in the book as to how this could have happened and what it has to do with the hunt for or the existence of the elusive Fourth Man. The suspicion is that it was primarily the publisher who wanted a reference to Putin in the title in the expectation that the book would sell better.

The reader can easily get lost in the many details of all the different cases discussed in The Fourth Man, although an index and numerous footnotes are conveniently provided. Nevertheless, the book offers a fascinating insight into a counterintelligence case or rather the limitations of such. In fact, as Baer himself remarks several times, most Soviet agents inside western services during the Cold War were not found out through logical deduction and analysis of files and timelines. It was almost always through important information from Soviet defectors or other sources from the opposing side that the CIA and other services traced them. That is what happened in the cases of Howard, Ames and Hanssen, too. When vital information from the opposing side is missing, the hunt for a traitor in the ranks all too often ends up targeting the wrong person. The history of western intelligence is rife with such ‘misdirected mole hunts,’ as they are sometimes called, and Baer’s book is therefore clearly not the final word on the Fourth Man. If there will ever be a final word, that is.