Cold War Intrigue Echoes Only Faintly as Ex-German Spy Testifies : Espionage: Aging Guillaume recalls intercepting secret 1973 letter from Nixon to Willy Brandt.

For addicts of Cold War cloak-and-dagger intrigue, this was the moment.

In all the public glare that German democracy could muster, Guenther Guillaume, the East German spy who pulled off one of the great coups in the annals of espionage, walked into a courtroom here Wednesday, called by the state to testify against his former chief, Markus Wolf, the Communist world’s most cunning spymaster.

Never mind that at 66, the ailing, gray-faced Guillaume had changed so much that Wolf later told reporters he hardly recognized him.

Never mind that the king of spy-thriller writers, Briton John le Carre, had recently dismissed as “nonsense’ in a letter to the London Daily Telegraph the notion that Wolf was the model for his compelling fictional character, Karla.

And never mind that the German government’s case against Wolf--three counts of treason and nine of bribery--is widely seen as riddled with absurdities.

Here, in open court, were the custodians of the Evil Empire’s deepest secrets, and one of them was talking.

Questioned mainly by the court’s grandfatherly chief judge, Klaus Wagner, Guillaume spent much of his 2 1/2 hours at the witness table discussing how he passed vital defense secrets of the Western allies to his masters while working as a close aide to then-West German Chancellor Willy Brandt in the early 1970s.

At one point, Guillaume told the court how, as the lone chancellery aide to accompany Brandt and his wife on a July, 1973, vacation to Norway, he watched as the local American ambassador handed the chancellor a top-secret letter from President Richard M. Nixon, only to have Brandt pass it over to him to be coded and sent to Bonn.

Guillaume said that before the vacation was over, he packed that letter, along with other sensitive documents, into an attache case, which he left in a hotel room for another of Wolf’s agents to photograph and take to East Berlin.

He said some of that information was so alarming that he seriously considered fleeing immediately with it to East Germany.

“It can happen that an agent comes across such explosive material, material that decides peace and war or that can cost a million deaths, that he decides it’s over, that he’s got to leave and take the information with him,” Guillaume told the court. He provided no details of what that material contained.

Guillaume’s arrest in April, 1974, led directly to Brandt’s resignation, effectively ending the career of one of the most important German statesmen of the post-World War II era. After serving five years of a 13-year prison term, Guillaume returned to East Berlin and a hero’s welcome in a 1981 spy swap.

Ostensibly, his appearance at Wolf’s trial was necessary to establish that Wolf directed his activities, a fact neither man disputed. The link is said to be required for the prosecution’s case, which hinges on the dubious hypothesis that Wolf can be convicted for betraying West Germany, a country to which he never belonged.

The fact that only a few minutes of Wednesday’s session were devoted to establishing this link left unclear the real meaning of Guillaume’s appearance. If the government’s intent was to underscore the evils of the East German system that Wolf directed, the star spy’s appearance backfired.

Instead, his recollections portrayed West Germany’s counterintelligence arm as a plainclothes version of the Keystone Kops. For instance:

* When Guillaume accompanied Brandt on the 1973 vacation in Norway, a tip-off already had cast suspicion on him. In his memoirs, Brandt recalls questioning the wisdom of taking Guillaume, but being reassured by security officials that his aide represented no risk.

* No one apparently missed the documents that Guillaume stole during the trip.

* One month later, a clumsy effort to photograph Guillaume’s wife by using a camera hidden in an attache case put the spy on guard and almost caused him to flee. Only later did he learn that the surveillance was to obtain security clearance for his wife; she had been offered a job at the West German Defense Ministry.