Latest spy saga illustrates Soviet bloc's `saturation' style. Espionage group with ex-US soldier worked for Hungarians, officials say

Doing battle against Soviet- bloc espionage is like trying to plug up a leaky dike: For every spy operation uncovered, there are others being formed or already in action. And so, intelligence experts say, the revelation of the latest alleged international spy pyramid, in which the West German government charges a retired United States soldier with selling military secrets to Soviet bloc intelligence for 10 years, comes as no surprise.

Not enough is known yet to assess the potential damage, but the case could have the makings of a major intelligence breach. Chief West German Federal Prosecutor Kurt Rebmann, in a statement yesterday about the arrest of ex-US Army Sgt. Clyde Lee Conrad, called the case ``especially grave.'' Alexander Prechtel, a spokesman for the prosecutor, said that Sergeant Conrad was the ``central figure'' in the case, that the alleged spy was based in West Germany, and that the case involved, couriers from Sweden.

The documents Conrad is suspected of copying and passing involved sensitive NATO defense plans for Europe, Mr. Prechtel said. He said he could not confirm that they included US Army contingency plans for a ground war in Europe against the Soviet Union.

Swedish authorities are holding two Hungarian-born brothers who admitted to working for Hungarian intelligence and are suspected by West Germany of being part of the Conrad operation. The brothers were caught Tuesday with radios and coded messages, according to a Swedish prosecutor.

US officials are being extremely tight-lipped on the matter.

Parallels are being drawn with the Walker family spy ring, one of the most serious US intelligence breaches ever. In that case, former US naval communicator John Walker was convicted in 1985 for selling Navy data to the Soviets for 16 years. Walker worked directly for the Soviets, whereas Conrad allegedly worked for the Hungarians, who work under the umbrella of Soviet intelligence. For Walker, the motivation was money. Prechtel said he could not rule out that Conrad had received ``millions of deutschmarks''. But for the two Hungarian-born brothers, the motivation may have been related to their nationality.

The Hungarian intelligence agency, Allamvedelmi Hivatel, is reputed to be one of the most skilled of the East bloc services. It is known for its skill in exploiting ethnic ties, in person-to-person contacts, subtlety, and patience, making the Hungarians especially suited for a long-term operation, says George Carver Jr., an intelligence expert at the Center for Strategic and International Studies.

Soviet bloc intelligence services use saturation techniques in their effort to recruit spies from the US military, making overtures to as many soldiers as they can in hopes that at least a few will take the bait. A common method, Carver explains, is to send a letter from a West German address offering money for research into unclassified matters. Once a person is hooked, he is lured into classified areas and offered increasingly large sums of money.

Until his retirement from the military in 1985, Conrad had access for seven years to military defense plans at the US base in Bad Kreuznach, Mr. Rebmann, the West German prosecutor, said. Conrad, who is reportedly from Ohio, served in the military for a total of 20 years. After his retirement, he tried to recruit soldiers for espionage, Rebmann said. The latest delivery took place last month in Vienna. The spy Conrad allegedly reported to lives in Austria, Prechtel said.

The spy network was uncovered by West German and US officials, with help from the FBI and the US Army.

Prechtel told a Monitor interviewer he did not know why Conrad's alleged spying activity, reportedly begun in 1980, was allowed to continue for so long. The prosecutor's office received the case two weeks ago, he said, but he did not know how long the West German Office for the Protection of the Constitution (the equivalent of the US FBI) had been on the case. ``This is something that shouldn't be allowed to happen, but always does,'' he said.

Prechtel said he did not think West German-Soviet relations would be damaged by the affair. ``It's, so to speak, the rule of the game that there are spies. We have to live with it, and everyone knows it.''

Melinda Crane-Engel, Frankfurt correspondent for Monitor television, contributed to this report.