Andrei Sakharov, the Soviet Union's most celebrated human rights activist, is urging the Kremlin to unilaterally cut the size of Soviet armed forces to build an "atmosphere of trust" between the world's two superpowers.

Sakharov also criticized the "breakneck speed" of the internal changes being put in place by Soviet President Mikhail S. Gorbachev and urged that they be subject to a national debate and either approved or rejected in a nationwide referendum. Such a step would be unprecedented."What is essential is sufficient time to consider and debate all of the changes, and a referendum on all of the reforms," the 67-year-old physicist said.

But later, answering what he said is the question he has most frequently been asked in the United States - whether the success of Gorbachev's program of restructuring, or perestroika, could be dangerous for the West - Sakharov said: "The danger lies not in its success but in its failure." And he said the Soviet Union clearly had "reached a dead end with its Stalinist, bureaucratic system."

Sakharov also called for changes inside the Soviet government to prevent future military involvement in countries such as Afghanistan.