The stations Posner discussed are Radio Liberty, which broadcasts Russian- language programs, and Radio Free Europe, which broadcasts to Eastern Europe. Both were funded by the U.S. Central Intelligence Agency until 1973, and they are now supported by Congress through the Board for International Broadcasting.
The Soviets have jammed Radio Liberty since its inception after World War II, and some Eastern European countries frequently interfere with Radio Free Europe. Despite the jamming, the signal can be heard sometimes in some places.
The jamming of radio broadcasts is outlawed by international agreements signed by the Soviet Union and other nations.
"I feel that jamming is counterproductive," Posner said during a question-and-answer session sponsored by the institute, a non-partisan research and educational group.
Posner, who stressed that he was not speaking on behalf of the Soviet government, said jamming Western broadcasts "attracts interest" and indirectly gives the stations more importance than they deserve. He implied that the practice tempted Soviets to tune in to Western broadcasts.
On another subject, Posner said the Soviets would pull their troops out of Afghanistan when that country was secure from outside intervention by Pakistan and other neighbors.
He said that the military presence gave critics of Moscow "a beautiful way of exploiting anti-Soviet sentiment" and that the longer the troops remained, ''the better it is for some people."
In fact, Posner said, "there are people in my country who think we ought to get out." But in a country with a population of 270 million, Posner said, it is natural that there would be some who disagreed with the action.
"The majority support it," he said.
Posner is visiting the United States to help arrange a televised exchange on June 22 between people in Boston and Leningrad. The program is to be shown in both countries.