CAMBRIDGE, MASS., JUNE 11 -- Richard von Weizsaecker, president of West Germany, called for a more cooperative relationship between Western nations and the Soviet Union in an address to the 336th commencement of Harvard University.

"Today we have a truly historical opportunity to engage in cooperation," he said, citing recent efforts of some Soviet leaders to liberalize their society. In a prepared text, Weizsaecker said, "It is not sufficient to wait and see in which direction the new thinking in Moscow moves. Fresh thinking is, first and foremost, a challenge to ourselves."

Weizsaecker spoke on the 40th anniversary of the Harvard commencement speech delivered by former U.S. secretary of state George C. Marshall that laid the foundation for the Marshall Plan through which U.S. aid helped rebuild Western Europe after World War II. His selection as commencement speaker provoked controversy.

Rather than seeking military solutions to conflicts in the underdeveloped world, Weizsaecker said, Western nations might instead consider development schemes like the Marshall plan.

Weizsaecker said Marshall's speech of 40 years ago "might almost have been conceived today, if only you replace the word 'Europe' by 'Third World.' "

Harvard Law School Prof. Alan Dershowitz joined in objections to Wiezsaecker's presence because his father served as a diplomat for Adolf Hitler and was convicted of war crimes at the Nuremburg trials. Rabbi Ben-zion Gold, chaplain to Harvard's Jewish students, said Dershowitz and other critics were "visiting the sins of fathers upon their sons."