The Rapacki plan, calling for a nuclear free zone in central Europe, still forms the core of Polish foreign policy Bohan Lewandowski. Polish Ambassador to the United Nations, said last night.

Leewandowski, in a speech to the Harvard-Radcliffe International Relations Council, suggested that the plan "is the only plan for nuclear disarmament which can be considered seriously by both East and West."

Although the Western powers feel that the removal of nuclear arms would enhance the Russian superiority in conventional weapons, Lewandowski suggested that recent military advances would remove this objection. "Ballistic weapons have now lessened the importance of nuclear weapons in central Europe," he said. "Besides, it is not at all certain that Eastern nations have a conventional advantage."

Lewandowski also emphasized the flexibility of the Communist system. "In Poland, most farms are not collectivized because such a system would not work now," he said. The Polish government is primarily concerned with economic progress and not with complete consistency among all socialist nations.

"Of course we feel that collectivization is ultimately the best way, but each socialist nation must adapt itself to the particular situation," Lewandowski said.