The arrests this week of ten Russian spies in the United States (another was picked up in Cyprus, released on bond, and has been missing ever since) have provoked an outpouring of news stories and commentary, not only here but abroad.  The FBI’s complaint includes scenes that appear to come from a John LeCarre novel, with Russian-born agents assuming false identities, living normal suburban lives, recovering money for expenses from dead drops and brush passes, and transmitting messages using steganography and wireless computer-to-computer transfers at neighborhood Starbucks stores.  Add in several glamorous female agents, and it's LeCarre meets James Bond—a sure-fire media winner.

As their lives and activities are put under the media microscope, we will undoubtedly learn a great deal more about those arrested.  The two Latinos living in New York were open left-wing radicals: Vicky Pelaez wrote odes to Fidel Castro’s Cuba and her husband, college professor Juan Lazaro, used his classes to denounce American imperialism.  By contrast, sultry Anna Chapman, built a real-estate business her attorney claimed was worth more than $2 million. 

There has already been speculation that despite years of residence in the United States, none of the accused had been able to gather and transmit any classified information. Since none has been charged with espionage, it is plausible that their actual value to Russia until their arrests had been minimal.  The charges they do face, money laundering and failure to register as foreign agents, carry substantial penalties, but apart from a message from Moscow suggesting that their major task was to get close to policy makers, there is little indication of what their masters wanted them to do.   That has led a number of commentators to dismiss this gaggle of agents as a bad example of a bureaucracy so addled that it spent large amounts of money to construct a spy ring whose tasks could have been met by anyone with access to the Internet. 

This dismissive response misses the point.  Russian intelligence, the SVR, made a very expensive, long-term investment by inserting these "illegals," as agents without diplomatic cover are known, into the United States with instructions to spend several years constructing new identities and burrowing deeply into American society.  The pay back in terms of espionage tasks performed (either procurement of information or, more likely, recruitment of sources with access to sensitive information and servicing those sources) would come only after five, ten, or more years of slow development. 

Long-term investments don't always pay off, and this one didn't.  On the basis of what is public at this point, the FBI monitored these Russian agents for years and then moved in and rolled them up before they could carry out any significant espionage.  From a counter-intelligence point of view, the FBI acted correctly.  The goal of counter-intelligence is to prevent the loss of sensitive information, not to wait until a serious loss of information has occurred, and then arrest the spy.  The fact that these agents have been charged only with money laundering and failing to register as foreign agents rather than for espionage is a counter-intelligence success, not a failure. 

But the fact that the FBI was able to disrupt this network before it did serious damage brings up a question that has not yet been addressed in the media coverage: How did the FBI get on to this motley collection of spies who hadn't actually yet done much?  Several of them arrived in the United States in the late 1990s, and by 2002, the FBI was monitoring their activities, eventually identifying the entire ring through meetings they held with each other, communications among them and between them and Moscow, and meetings with “legal” Russian officials.  But what provided the first clue to American counter-intelligence?  How did it know where to look?  There is not a hint in the FBI affidavits and legal complaints about how the FBI got on to these "sleeper" agents. 

Historically, the FBI learned of Soviet spy rings by one of four techniques.  First, someone defected and exposed an espionage network.  Whittaker Chambers outed Alger Hiss, albeit years after Chambers defected.  In the classic case, the most devastating blow to Soviet intelligence in the United States came when Elizabeth Bentley, a courier for a Soviet spy ring, embittered by KGB efforts to reduce her role, went to the FBI in 1945 and named dozens of government officials as sources.  She also identified several KGB officers with whom she had contact.  Dubbed the blond spy queen by the media, the decidedly unglamorous (and brown-haired) Bentley had no documentary evidence that could be used in court.  Aware that her unsupported testimony (that she was alcoholic, neurotic, and promiscuous didn't help) arrayed against the denials of respectable government officials would be a hard sell in court, the government declined to indict anyone on her evidence alone.  But from a counter-intelligence perspective that didn't matter.  Her evidence allowed the FBI to identify those government officials who were spying for the Soviets, and to swiftly force them from government service and end their careers as spies.

The second technique used to expose spy was signals intelligence.  Beginning in 1945, American cryptanalysts began to read KGB communications sent between Moscow and its stations in America.  Released to the public in 1995, the Venona decryptions reassured the FBI that Bentley had been accurate and also uncovered hundreds of other Soviet spies.  This evidence, however, was deemed too sensitive to be used in an open court, since it would reveal to the Soviets that their codes had been broken.  But, again, it allowed the FBI to identify who had been assisting the Soviets and to put an end to their access to sensitive information.  The FBI also approached some of those named in Venona and, in return for immunity, got them to cooperate.

The third way that spies were exposed came from disgruntled Soviet KGB officers.  In 1943, J. Edgar Hoover received an anonymous letter in Russian from someone purporting to be a Soviet intelligence officer, naming a number of employees of the Soviet embassy and consulates as agent handlers.  Initially suspicious, the FBI eventually concluded by surveillance that the letter was accurate; American intelligence later learned that a mentally unstable and bitter KGB officer at the Washington embassy had sent it.  The FBI tracked several of those named as they met sources, and so ratcheted up its surveillance that one of them, Semen Semenov, found it impossible to meet his agents, necessitating his recall to Moscow.  The one American named in the anonymous letter, Boris Morros, was recruited by the FBI as a double agent.  After observing another KGB officer named in the letter attempting to recruit sources in the American aircraft industry, the FBI approached those Americans and turned them into double agents who fed the Soviets aviation intelligence that had been sanitized by the FBI. 

The fourth way to expose a spy ring is to reap the benefits of poor tradecraft by either Russian officers or American agents.  The FBI identified several Soviet diplomats at the Soviet consulate in San Francisco as likely Soviet intelligence officers in 1943 and put them under surveillance.  The Soviet officers failed to realize they were under scrutiny, and the FBI eventually identified several physicists at the University of California Berkeley as being in contact with Soviet intelligence.  One immediately lost his job with the Manhattan atomic bomb project and another was prevented from joining.   In 1953, a New York newspaper boy noticed that a nickel in the change he had been collecting for a copy of the Brooklyn Eagle felt light.  He dropped it, it split open, and inside was a small microfilm.  He mentioned this to the daughter of a New York policeman, who told her father, and eventually the FBI got the film.  It contained numbers typical of the "one-time pad" cipher system used by Soviet intelligence.  The FBI concluded that a very careless Soviet illegal had mistakenly paid for his newspaper with the wrong nickel. The Bureau was not able to pin down who had done so at the time but after the Soviet illegal Reino Hayhanen defected in 1957, his information allowed the FBI to identify the message as directed to Hayhanen himself and conclude that either he or his superior, the Soviet illegal Rudolf Abel, had lost the hollow nickel.  Not long after Abel was arrested.

Which of these techniques led to the exposure of this ring?  Certainly the SVR, which has seen a major investment in manpower, money, and time explode in its face, will want to learn how its agents were identified so that next time they can do it right.  Very likely for that reason the FBI will not wish to disclose how it got on to these sleeper agents so early.  If these accused Russian spies refuse to plead guilty, they may press their defense attorneys to challenge the warrants that enabled the FBI to wiretap them, enter their homes surreptitiously, and access their computers, in order to learn how they came under suspicion.  Did some signals intelligence breakthrough or lapse alert the government?  Did one of the agents have some kind of glitch with his or her false identity that caused suspicion?   The FBI's affidavit reports the surveillance of several Russian diplomats who met covertly with one or another of the illegal agents.  These officials were obviously Russian intelligence officers who had diplomatic cover.  Did one of these "legals," as they are known, fail to shake off a tail on the way to a meeting?  Was one of their official Russian handlers an FBI informant?  Does American intelligence have a mole of its own in Moscow Center who alerted his handlers to this ring? 

We may never know the answer to how this counter-intelligence triumph took place.  Russian intelligence is probably more worried about that question than the fates of its spies.   Like in those old LeCarre novels, intelligence failures always open up the possibility that something is rotten in the organization.  And somewhere in Moscow, there are no doubt a lot of people trying to figure out what went wrong.

Harvey Klehr and John Earl Haynes are co-authors, with Alexander Vassiliev, of Spies: The rise and Fall of the KGB in America (Yale University Press).