One of the most despicable Soviet apparatchiks in decades was wined and dined in Washington last week as part of the Soviet entourage at the summit. His visit was unprecedented in U.S.-Soviet postwar history.

The man was Gen. Vladimir Alexandrovich Kryuchkov, deputy chairman of the Committee for State Security. That is English for Komitet Gosudarstvennoy Bezopasnosti, the KGB.

Kryuchkov is no run-of-the-mill spy. He was behind the assassination of Afghan President Hafizullah Amin in 1979 and maybe even the attempted assassination of Pope John Paul II. He oversees KGB officers who infiltrate the United States. It is likely he approved the jailing of U.S. News & World Report Moscow correspondent Nicholas Daniloff last year. He engineers the theft of Western technology. He has seduced, bribed and otherwise used American traitors. He has resorted to murder and torture to further communist ends.

The State Department knew Kryuchkov was among the 250 Soviets in town for the summit. A department spokesman expressed surprise that no one called it to public attention then.

The spokesman speculated as to why Kryuchkov had the nerve to show up here. The KGB's highest-ranking man wanted to supervise the protection of Mikhail Gorbachev and he was needed as a knowledgeable analyst on how the KGB will verify U.S. compliance with the disarmament treaty.

But a third reason, according to other sources, is Gorbachev's need to have the KGB in the picture whenever he makes an important move. The KGB is a continuing patron of Gorbachev's power. "It shows that Gorbachev really relies a lot on the KGB," a CIA analyst said.

Kryuchkov is one of several deputy KGB chairmen, but he is head of the First Chief Directorate of the KGB.

The bulk of KGB activity is targeted against Soviet citizens, with the KGB acting as a pervasive secret police force. But the First Chief Directorate, which Kryuchkov has headed since at least 1973, conducts all the KGB's operations abroad. "He's the guy who chases Americans {and others} all over the world," an ex-KGB official told us. And Kryuchkov is the first man in that job allowed to visit the United States.

Consider the departments Kryuchkov has presided over during 14 years in his job.

Directorate S is responsible for infiltrating KGB officers illegally into the United States. Did Kryuchkov meet with any of his deep-cover agents in Washington?

Department Eight of Directorate S is responsible for assassination and sabotage. A persuasive case has been made that the KGB was behind the Bulgarian-directed attempt on the life of Pope John Paul II. If so, then it was Kryuchkov's work. How does that strike American Catholics who watched the fawning over our Soviet guests last week?

Directorate K is responsible for all penetration of foreign intelligence services. So the top KGB man trying to place a mole in the CIA was in Washington last week.