President Carter's former national security adviser, Zbigniew Brzezinski, has called on western leaders to "move beyond primitive and undiscriminating anticommunism" and develop a new strategy for dealing with Moscow that could "break the increasingly dangerous stalemate" between East and West.

Brzezinski, in a speech prepared for delivery today in Helsinki, Finland, says he harbors no illusions that tensions can be promptly eased.

But he argues that "we may be faced with acute intensification of the already unstable American-Soviet rivalry" and rather than stand pat, western leaders should undertake a common reexamination of East-West relations and confront Moscow with proposals that at least have a chance of resolving the most critical disputes.

On the now almost two-year-old Soviet military occupation of Afghanistan, Brzezinski says the West might suggest "a comprehensive guarantee" involving the West, the Soviets and other neighbors of Afghanistan that would reestablish that country's traditional neutrality in a way that does not threaten Moscow. He suggests temporary stationing of troops there from Moslem countries, such as Algeria, that have good relations with the Soviets.

On Poland, Brzezinski calls "a long-term program of economic development assistance, tied to some supervision by the International Monetary Fund, and reinforced by a visibly demonstrated act of national reconciliation within Poland itself." Brzezinski believes such an approach would be "more constructive" than the limited sanctions now being imposed by the United States and would also do more to heal the rift in this country's relation with allies over the sanctions.

On the nuclear arms competition between the two superpowers, Brzezinski recommends that the United States skirt talks in Vienna about mutual East-West troop reductions, which are bogged down in detail, and propose a straight reduction of American battlefield nuclear weapons in Europe for a reduction in the number of Soviet tanks deployed in East Germany.

Brzezinski said he does not agree with the assessment made by President Reagan earlier this year that the West is inferior to the Soviet Union in strategic nuclear striking power. "From everything that I know -- and in recent years I came to know almost all that could be known -- I conclude that the true and accurate state of the military relationship is that of strategically ambiguous equivalence." In other words, he said, "the U.S. is clearly ahead of the Soviet Union in some key systems, and the Soviet Union is clearly ahead in others."

"It all adds up," Brzezinski continued, "to the simple proposition that neither side can be very certain about the consequences of a military engagement, and even less so about the consequences of quick preemption." Moreover, he said, neither side can count on intimidating the other through the threat of power.

Brzezinski also urged that an annual summit meeting be held between leaders of both countries. The former top Carter administration official, who was widely regarded as an anti-Soviet hard-liner while in office, said infrequent summits coming years apart tend to generate excessive expectations that can cause "damaging swings from hysteria about the Cold War to euphoria about detente."

Brzezinski argues that annual meetings are a more stable and rational approach and are more likely to produce "greater understanding of our respective positions."