The 35-nation Conference on Security and Cooperation in Europe resumes today in Madrid amid growing East-West tensions as well as questions about allied unity.
A series of such meetings have been held since the signing of the Helsinki Final Act in 1975 covering human rights and security issues. When the most recent meeting broke up in March over Western opposition to the imposition of martial law in Poland, the United States position was that continued talks would be fruitless unless the human-rights situation in East-bloc countries improved.
If anything, the situation has gotten worse, American officials say. The Polish trade union Solidarity has been outlawed. Soviet forces remain in Afghanistan. There have been new crackdowns on Soviet dissidents and a clampdown on contacts between Soviet citizens and Westerners.
But the United States is returning to Madrid, chief US negotiator Max Kampelman says, because ''it's important that we keep talking to the Soviets.''
It is also important, the American diplomat acknowledges, because there have been new challenges to the Western alliance in recent months, challenges that the Soviet Union would be able to exploit more successfully if the US were to turn its back on the Helsinki process.
Among these: disagreement over the Soviet gas pipeline and US sanctions, increased questions about the deployment of American Pershing II and cruise missiles on European soil, and a more costly and aggressive conventional deterrent strategy for NATO being advocated by the Americans.
In addition to these concerns are new governments in some European countries attended by some political instability, heightened attention in Moscow around the eventual successor to Soviet President Leonid Brezhnev, and increased saber-rattling between the two superpowers that many Europeans find frightening.
Interviewed by American reporters for a Voice of America radio broadcast, Dr. Kampelman said he is ''not optimistic'' that new agreements can be reached on the substantive human-rights and security issues to be discussed at Madrid beginning Nov. 9. But, he said, he is confident the Western allies can remain united in insisting on improvements in human rights before moving on to ''business as usual'' in security areas.
The allied representatives are returning to Madrid, having met in Norway, Portugal, and Brussels in recent weeks to discuss strategy and a common position.
''Yes, there are tensions (among the allies),'' Dr. Kampelman said. ''But I feel rather confident that the unity and values that we have will prevail, and that this will continue to express itself in Madrid.''
While the Western representatives are likely to stand together in their criticism of human-rights violations by the Soviet Union, there will be discussion of - and no doubt differences over - proposals to reduce East-West military tensions. A number of proposals have been offered by the so-called ''neutral and nonaligned'' nations, including ''confidence-building measures'' designed to reduce the likelihood of surprise attack or accidental armed confrontation.
Key issues here remain unresolved, however. For example, the original Helsinki agreement includes notification of troop movement of more than 25,000 anywhere in Western Europe or east to a point 250 kilometers within the Soviet Union.
The allied position is that it should be extended eastward to the Ural Mountains to include all of European Russia. The Soviet response has been ambiguous and seems to indicate an insistence that the ''zone of applicability'' be extended westward at the same time to include all of the Atlantic Ocean.
''The allies won't accept that,'' Dr. Kampelman says.
In any case, such questions are unlikely to be resolved without East-bloc improvements on the human-rights issues covered by the Helsinki Final Act of 1975.
''We must understand that the premise of the Helsinki Final Act is that peace , cooperation, and security are part of a totality which is balanced,'' Ambassador Kampelman said. ''The Helsinki Final Act was not just a military security document, but a human-rights document.''
Whether Mr. Kampelman's fellow negotiators from the West fully agree remains to be tested.