Soviet leader Lenoid Brezhnev asserted today that the Carter administration's new nuclear policy is "extremely dangerous" and underscored Soviet readiness to open immediate talks on limiting medium-range nuclear missiles in Europe.

Brezhnev spoke with contempt about American retaliatory measures, undertaken in the wake of the Soviet invasion of Afghanistan.

"So what?" he said in a nationally televised speech as he pointed out that the Soviets had managed to hold "very successful" Olympic Games and buy wheat and technology from other Western countries. He said that his recent meetings with the leaders of France and West Germany "convincingly" demonstrated the failure of U.S. efforts to isolate the Soviet Union.

He emphasized Moscow's commitment to Afghanistan's Soviet-backed government, saying, "None should have any doubts about it." He pointedly warned Pakistan about activities of Afghan "counterrevolutionaries" on Pakistan soil.

But the Soviet president avoided all references to the unrest in Poland as he outlined the main points of Soviet foreign policy. The omission was in line with Kremlin efforts to avoid public comment on the conflict between the Polish government and strikers.

Brezhnev appeared strong and vigorous as he spoke at an observance marking the 60th anniversary of the founding of Kazakhstan, a Soviet republic. The celebration took place at Alma Ata, the capital of the Central Asian region. It was his first foreign policy speech since Last June, but Western diplomats said it contained no signals of any shift in the Soviet position on key international issues.

His remarks dealt mainly with nuclear weapons and appeared aimed at West European capitals rather than Washington. Brezhnev voiced "concern" about what he termed a "U.S.-imposed" decision of the North Atlantic Treaty Organization to deploy 572 medium-range U.S. nuclear missiles in Europe by 1983.

Referring to his earlier proposal for negotiations on the medium-range missiles in Europe, Brezhnev said: "From the leaders of the Western powers we expect a reply to our proposals, we are ready for concrete deeds -- and we expect the same from them."

He coupled that with a denunciation of President Carter's new strategic doctrine, which envisions the possibility of limited nuclear war. Brezhnev described the president's recent directive as "the talk that has nothing to do with reality and that only deludes people."

That policy, he continued, is "extremely dangerous" for the world and it is "hard to imagine" that it is being advanced by the "government which has signed the agreement with the Soviet Union on the prevention of nuclear war."

American foreign policy makers, he said, "do not see or do not want to see historic changes on the world arena [and] the new balance of forces." He said that the United States will not be able to dominate the international scene again "by saber rattling," adding that "one should believe that sooner or later the U.S. leaders will come to such a conclusion."

Brezhnev's position on Afghanistan echoed his first public statement following the intervention last December. Soviet troops would leave, he said, as soon as the reasons for their entering Afghanistan ceased to exist -- that is, when all resistance to the Kabul government is eliminated.

Brezhnev said the threat to the Soviet-installed Kabul government continues to exist and that the "services of China, just as those of Pakistan, are being zealously used" by American "imperialists" who seek to stifle "the Afghan revolution" and turn that country into an enemy "threatening the Soviet Union."

The Soviet leader also voiced standard fears about Chinese-American collusion against the Soviet Union and about forces trying to push Japan "down the path of militarism and actions hostile to the Soviet Union."

There were no phrases, which used to be standard in soviet pronouncements, about the need to improve ties between the two superpowers. Analysts noted that Brezhnev made no mention of SALT II or U.S.-Soviet strategic arms limitation talks in general.

Brezhnev's tone was sober and he concluded that the intentional situation "is not an easy one." He declared that the main goal must be to prevent "the flywheel of the arms race from picking up a new and quite dangerous speed."