COLUMN ONE : Scientist for the Enemy : Brooklyn’s Joel Barr played a key role in aiding the Soviet military. Now 76, he voices regret--and collects U.S. Social Security. Congress members call for an espionage investigation.

In America, he is known as Joel Barr, an enthusiastic Communist from Brooklyn who disappeared without a trace in the late 1940s.

In Russia, he is known as Iosif Veniaminovich Berg, half of a team of brilliant Americans who designed the first Soviet computer and pioneered the microelectronics industry so critical to the Kremlin’s defense machine.

But in his St. Petersburg apartment, he is just a 76-year-old eccentric--balding, stooped and worried that the modest attention he has received since he came out of hiding will bring troubles he avoided for more than 40 years.

Sitting at a kitchen table recently with his worn Soviet passport and newly acquired U.S. passport, Barr said he now believes that working for the Soviet defense industry was wrong.

“I am ready to confess, or whatever the word is, to say that really I made a tremendous mistake,” he said. “Knowing what I do now, it was a tremendous mistake to have done what I did.”

He insists he never meant for his work to “put the United States in peril.” Instead, he was motivated by a desire to help communism thrive in Russia, so someday it would spread to America.

Other Americans immigrated or defected to the Soviet Union over the years--some because they had worked as Soviet spies and others because they believed communism’s promise of a better future. But Barr and his partner stand out because they had such a significant impact on Soviet industry and military strength and because the question of whether they were spies is still shrouded in mystery.

Barr’s admission of error is not likely to melt any hearts in Washington, where two dozen Congress members have denounced him as a traitor and called for an investigation into the espionage issue.

In a letter to Atty. Gen. William P. Barr this summer, the Congress members charged that Barr “has publicly admitted to using skills and information derived from his work on classified U.S. military projects to aid the Soviet Union in developing deadly military weapons, including radar-guided antiaircraft guns.”

When Barr first heard about the charges, he was stunned. “Some congressmen want to kill me--or castrate me or something,” Barr said in a panicky voice.

He admits to having helped build the first Soviet radar-guided antiaircraft guns but contends: “Nothing I did in America was used directly in my work in the Soviet Union; but indirectly, my general education, which I got in America, has helped me a lot in my work here.”

Asked whether he felt remorse that his know-how had been used in the Vietnam War to shoot down American airmen, Barr seemed baffled and shaken. He excused his actions by saying that it was a bad war that millions of Americans opposed. If helping create an antiaircraft weapon makes him a criminal, he adds, then the inventor of gunpowder should be considered an enemy of humanity.

But others believe Barr was part of the espionage ring of Ethel and Julius Rosenberg, who were executed in 1953 for passing atomic bomb secrets to the Kremlin. Among the accusers is Robert Lamphere, a retired FBI agent whose work in cracking a KGB code in 1948 led to the Rosenbergs.

“I think he’s a spy and a traitor, and I feel very angry about the fact that he can come back to America and get a U.S. passport,” Lamphere said.

The FBI had suspected Barr of being a spy in the late 1940s and followed his movements in France, where he was studying, Lamphere said, but then the agency lost him. There was not enough evidence to extradite him or bring him to trial at that time, nor would there be enough now, Lamphere said.

Morton Sobel, a college chum of Barr who stood trial with the Rosenbergs and was sentenced to 30 years in prison for conspiracy to commit espionage, recalls that when he was questioned by a U.S. attorney after his arrest in 1950, he was told, “We have Barr cornered in Paris, and we’re going to get him, too.”

But Sobel, who served 18 1/2 years in prison and still contends he was innocent, said that, as far as he knows, Barr was not a spy.

In the past year and a half, Barr has made three trips back to the United States and resumed long-severed relationships with friends and relatives. But his brothers, who were hassled on his account for 20 years by FBI agents, refuse to speak with him.

“I’ve spoiled my relations with my family,” Barr said. “They all think I’m making a lot of money out of this. They’re scared to death that they will suffer again because of me. Who wants to have dealings with a guy whose family has a black sheep as black as me?”

Barr re-established his American identity three years ago when two of his four children, both Czechoslovak citizens, were trying to defect to the United States while on tours in Western Europe with music groups. Aided by Barr, who went to the U.S. Embassy in Prague to establish that their father was American, they succeeded.

A year ago he sought his own U.S. passport, hoping to find American investors for a machine designed to inexpensively manufacture microchips. While in the United States on a Soviet passport, he applied for a U.S. passport like any other American--through the passport office of the Immigration and Naturalization Service.

On that trip he was surprised to find that many elements of socialism have become part of American society, and he is gladly taking advantage of some of them.

Although he still lives and works primarily in Russia, Barr now receives Social Security benefits of $244 a month--which he began getting after simply applying for them. He claims California residency, and when he is in America, he said, he also collects a state supplement to his Social Security that almost doubles his benefits.

“It galls me that a guy who works for a foreign power that is basically our enemy for 30 or 40 years can now be drawing Social Security,” Lamphere said. “There’s something wrong with our system.”

But Barr says he deserves his benefits because he paid into the Social Security system as a young man. Wondering aloud how accusers expect him to atone, he said: “What am I supposed to do--go into a nunnery or something?”

If Americans consider his life from his point of view, he argues, they will see that each step seemed logical to him at the time and that he, too, in his own offbeat way, is really a “patriotic American.”

“Nothing that I did was against the American people,” he said. “I was working to create a system that would have more justice and not so much suffering” and then bring it back to America.

Raised in Brooklyn by parents who had emigrated from Russia, Barr says his most vivid childhood memories are of newspaper photos showing businessmen jumping out of windows during the stock market crash of 1929 and of Depression days when his industrious father could not feed the children.

In his neighborhood, soapbox politicians preached about an alternative system that would end America’s poverty forever. He read books about communism and joined the Young Communist League.

As an idealistic youth at City College of New York, he was drawn to a group of young intellectuals planning to remake America on the models of Marx and Engels. Julius Rosenberg signed up young Barr for the Communist Party, and they became good friends.

“Half of our electrical engineering class at City College was in the Young Communist League,” Sobel recalled. “You have to understand, 1938 was a very special time. We were fighting against fascism. Some from our class even went off to Spain to fight (on the side of the Communist-aided loyalists) against the Fascists.

“We were all very idealistic,” Sobel added. “Joel fit into this mold.”

After a long job search following graduation, Barr’s career finally took off, thanks to America’s World War II industrialization, and he worked both for the government and for private companies. But after the war, he was fired from a high-paying job at Sperry Gyroscope, a defense contractor, when it was learned that he was a member of the Communist Party. He admits to having lied about it on his job application.

Drawing on his savings, he was able to get a master’s degree at Columbia University and to travel to Europe. About the time the FBI was moving in on the Rosenbergs, Barr decided to travel from Paris, where he was studying music composition, to Prague, to get his first glimpse of socialism in action.

“I was amazed that I did not meet anybody who was praising the government,” Barr recalled. “I expected everybody to feel they had won a tremendous victory and say, ‘Now we are free; now we can build this new society.’ But instead they were very, very angry.” The Czechoslovak lack of Marxist enthusiasm, however, did not dampen his own convictions about communism.

He heard of the Rosenbergs’ arrest and the harassment and imprisonment of friends. Convinced that the same awaited him, he followed the advice of Czechoslovak Communists, changed his identity--calling himself Joseph Berg from Johannesburg, South Africa--and ceased all communications with family and friends in America.

“When I was in Europe, it was the McCarthy era in America, and my friends were being persecuted and arrested,” Barr said, referring to the Communist-hunting hearings conducted by Sen. Joseph R. McCarthy in 1953-’54. “I felt the country was moving toward fascism.”

In Czechoslovakia, he was joined by a friend and former colleague, Alfred Sarant, who had fled the United States in fear of arrest, and they began working in electronics. Barr married a Czech woman and started a family. He kept his real identity secret even from his wife, Vera, who learned the truth only after 20 years of marriage.

Then-Soviet leader Nikita S. Khrushchev, knowing that his country was trailing in the superpower arms race because of its inferiority in electronics, invited the two American engineers to Russia in 1956 and set them up in their own institute in Leningrad, as St. Petersburg was then known.

They were treated there like celebrities, with government cars and salaries many times those of Russian counterparts.

Russian colleagues credit Barr and Sarant with being the fathers of Soviet microelectronics, which enabled the regime to compete in the Cold War arms race and thereby strengthen its position at home.

“I think communism would have fallen apart earlier if not for them,” said Raphael A. Lashevsky, a lab chief at Svetlana Electronic Devices Manufacturing Corp. in St. Petersburg, the huge electronics enterprise where Barr still works. But Lashevsky said he, like Barr, did not think of the dramatic political implications of their work until recently.

Friends and colleagues say that Sarant, known in Russia as Filipp Georgievich Staros, was a perfectionist and the leader of the two. Barr, they say, was “childlike,” capable of bizarre and careless behavior.

The decor of Barr’s St. Petersburg apartment is testament to his eccentricity. The floors, panels and makeshift furniture, all fashioned out of the same thin wood squares, have jagged edges and strange shapes and give the impression of a gigantic furnished treehouse.

His command of Russian also shows a propensity to cut corners. After 40 years as his main language, even spoken with his children, Barr’s Russian is ungrammatical and carries a thick Brooklyn accent.

Barr “was always secondary,” said Leonid P. Kraismer, a professor who wrote a book on the development of Russian cybernetics and first met the Americans in the late 1950s. “Berg was a very nice man; we loved him,” Kraismer said, calling him by the name he uses in Russia. “But Berg could not compare with Staros. Berg was a man who always had fantastic ideas, and only about one in 100 were usable.”

Barr was crushed by Sarant’s death in 1979. After their children were grown, Barr and his wife separated; she now lives in Prague.

With his old friend dead and his wife gone, there may be no one left who really understands Barr. Even people who have known him for decades describe him as enigmatic.

The loquacious Barr, who loves to be the center of attention, does not hide his vanity. He was eager that photos taken for this story be printed in color because, he said, black and white would not do him justice. And he seems certain that his life story could be turned into a best-selling book in the hands of a talented author; he has an American agent working to find one.

It has always been important to Barr to keep company with famous Russians and to entertain them in his own unique way. His six-room apartment--a mansion by Soviet standards--has been the site of countless musical evenings. Stars joined in jam sessions with Barr’s four children, all of whom graduated from Leningrad Conservatory.

Barr’s longtime mistress, who asked not to be named, recalled that through the decades Barr and Staros’ socializing often took on a political tone. They played the role of Communist evangelists, she said, who tried to draw back into the fold the Russians who had long since become disillusioned with Marxist-Leninist ideology.

“They were true believers,” she recalled.

Barr’s commitment to communism remained strong even after the crimes of dictator Josef Stalin were partially revealed by his successor, Khrushchev. Barr says he abandoned his faith in communism only after Mikhail S. Gorbachev came to power and more fully disclosed the atrocities of past regimes. He spent no time mourning the death of the theory he had served during his whole adult life.

“I have a peculiar character,” he said. “I don’t waste my time crying over spilled milk.”

Now he has become a troubadour for the American dream.

“I believe that now history will show that the Russian Revolution was a tremendous mistake. It was a step backward for mankind,” Barr said with a smile. “The real revolution for mankind that will go down for many, many years was the American Revolution.”

His new heroes are America’s founding fathers, because they created a system that is resistant to dictatorship. “These guys were geniuses much more even than Lenin,” he said. “And this was a lot for me to say, considering my history.”

Instead of preaching communism to Russian friends, he spends his time thinking up ways to convince his still-radical American friends that Marxist-Leninist theory is fatally flawed.

For now, he plans to spend most of his time in Russia.

“Here I am a rich scientist, and in America I’m just a poor pensioner,” he said.

But he does plan to keep traveling back and forth to America to visit friends and family. He is still seeking funding for his “mini-fab,” the invention for making microchips. Either that way or by selling his life story, he hopes to become a quick millionaire.

“He thought he could find 1,000 investors by putting an ad in the New York Times,” his old college friend Sobel said. “He has no concept of how things are done in this country. He has been Russified. His thinking is like that of a Russian.”

Special correspondent Natalya Shulyakovskaya contributed to this story.