WASHINGTON (AP) _ On her trips to Moscow, Barbara Makuch would take bottles of Scotch to KGB and Communist Party officials. On her return home to Buffalo, she brought information to the FBI.

For 20 years, Makuch, 39, was a double agent, working both sides of the Cold War. The FBI knew about her other life; the KGB didn't.

She wasn't a spy in the classic sense. Her job, rather, was to enable the Soviet Union to influence public opinion in the United States.

She would have Soviet diplomats and journalists to her house for dinner. Some of them were what they said they were. Others were spies. They would ask her to arrange for them to give speeches or meet with Americans to defend Soviet policies - the invasion of Afghanistan, the 1983 downing of a Korean passenger plane.

She would take them to see Niagara Falls. Some of them asked to see Love Canal - an example, they said, of American urban and cultural decay. Others wanted to see a nearby air force base, which she couldn't arrange.

Through it all, she would report her guests' every move to the FBI. Sometimes, she carried a bugging device in her purse. Often, the FBI would use her information to track the Soviets' activities, to see whom they met, what they photographed.

Much to her relief, it's all over. And she can talk about it. She almost can't stop talking about it.

''It's like clearing out your system,'' she said.

The lid was lifted off her career as an FBI ''asset'' - the agency's term for a source of information - when the Rev. Alan Thomson pleaded guilty May 21 to bringing money from the Soviet Union and deliberately failing to report it to Customs authorities.

Thomson is a Presbyterian minister who served as director of the National Council of American-Soviet Friendship, a group founded by the U.S. Communist Party in 1943 to advocate Soviet views and policies.

The FBI had claimed for years that the council was one of several so-called front organizations directed and financed by the Soviet Communist Party to spread propaganda and sow disinformation in the United States.

But the government didn't have a case until Makuch told the FBI early in 1987 that Thomson had brought back money from Moscow and wanted her to deposit some of it in the bank.

On Feb. 6, 1987, Makuch flew to Washington where she had lunch with Thomson and took him to her room at the J.W. Marriott Hotel. There, he gave her $17,000 and instructions on how to deposit the money in a way that the bank wouldn't have to report it to the government. Next door, the FBI was running a video camera and Thomson was arrested two years later.

Makuch said she started reporting to the FBI after she met a young pro- Soviet radical who said he planned to plant a bomb and carry out other violence to protest the Vietnam war.

The FBI asked whether she would keep in touch with the radical and his friends and keep reporting to the bureau. She agreed.

''My grandmother's first husband was hanged by the Communists. My uncle was shot by the Communists for refusing to remove a cross from the wall. I was raised being afraid of the Communists,'' said Makuch, who was born in Germany to a Ukrainian mother and Polish father and came here in 1966 at the age of 14.

Through her new friends, she was recruited to join the youth organization of the U.S. Communist Party and then the party itself. She was encouraged to open an office of the Friendship Society in Buffalo. She held various jobs coordinating U.S. and Soviet exchange programs.

She lived in constant fear of being found out by the Kremlin, especially after several Americans defected to the Soviet Union in the 1980s. She had visions of Lubyanka - the feared KGB jail - every time she stood in the passport control line at the Moscow airport.

Her Soviet hosts would ask her questions. Six months later, they'd ask the same questions - just to see if she had told the truth the first time.

Her daughter, 19, grew up believing her mother worked in international cultural exchanges. As she got older, ''she suspected her mom did something for the government.'' But Makuch couldn't tell her the truth until recently.

''That was hard,'' she said. So were other things.

Her husband, also 39 and of Ukrainian origin, was in ill health and had two kidney transplants. Makuch said the KGB tried to recruit him, but he refused. But he knew of his wife's double life, and traveled with her to Moscow several times and held her hand through difficult times.

There were times she had to make excuses for the Soviet invasion of Afghanistan. But she drew the line at defending the Soviet downing of a Korean jumbo jet when the passenger liner strayed over Soviet airspace in the North Pacific.

She was paid by the FBI - ''not very much'' - but hopes to improve her finances now by writing a book and doing business with some of the independent republics that emerged from the Soviet Union.

And if she goes back, she'd like to see some of her former Soviet contacts.

''Some of them were very nice people,'' she said. Besides, ''I respected the KGB as adversaries.''