THE astonishing case of Vitaly Yurchenko, the double defector who has gone back to the Soviet Union, is the latest of several recent instances in which security on one side or the other of the Iron Curtain has been compromised. Soviet-bloc spies have been unearthed in Britain, West Germany, and the United States. Since May, two Soviet intelligence agents and an East German diplomat have defected to the West. And now Mr. Yurchenko. The layman is in no position to know whether it is the Western alliance, or the Soviet bloc, that in the aggregate most benefits from the two-way leak of classified knowledge. Perhaps no one knows.
Successfully debriefing a defector requires balance. He (or she) should be made to feel comfortable, at home, and trusted, so that he will tell as much as he knows. At the same time he must be scrutinized in an effort to make certain that he is a genuine defector, not an intelligence plant. And if he is one of the many who at times feel isolated or long for the homeland, the CIA needs to act to counter these attitudes, lest redefection occur.
The challenge is particularly difficult in a democracy. Its security agents need to learn as much sensitive information as they can, and guard against either foul play from East-bloc agents or redefection. Yet the defector has to be allowed some of the personal freedom that was, in many cases, a prime motive for switching allegiance, lest he conclude that freedom was a mirage and consider going back home.
The Central Intelligence Agency has successfully handled defections of Soviet and East-bloc citizens, some of whom possessed sensitive material. But the CIA mishandled the Yurchenko case.
Whether he was a genuine defector who had a change of heart, as many intelligence specialists think, or a Soviet plant who all along intended to return to Moscow, the CIA at some point ought to have sensed that he might redefect. It apparently did not. If Yurchenko's original defection was genuine, and he was feeling the temporary sense of isolation and longing for his homeland that other defectors at times have felt, the CIA could have taken steps to try to counter such feelings.
The Yurchenko instance leaves one uneasy about current CIA checks into whether a purported a defector is sincere or a plant. President Reagan himself admitted his own unease about this point.
In the course of debriefing defectors, how much information does the US give away about how Western intelligence works which would be valuable to the Soviet KGB, should the presumed defector again go behind the Iron Curtain?
Other questions emerge from the case of former CIA agent Edward L. Howard, thought to have provided the Soviets with some US secrets. One concern is the best way to handle the dismissal of security-agency employees who possess sensitive information when it is decided that they should be fired, as Mr. Howard was. Some means should be found to handle this situation without so angering the employee that he decides to sell his secrets to an adversary.