Washington — Cries of alarm rise here over a threat to the unity of the United States and its European partners.
Officials of the European Economic Community (Common Market) are in Washington to see if differences can be reconciled. On July 15, the EEC formally protested the extension of a US ban on the sale of oil and gas equipment to the Soviets to European firms making such equipment under American license.
Meanwhile, a former secretary of state, Edmund S. Muskie, pleaded with President Reagan at a meeting here to get his house in order.''A policy gap,'' he charged, ''is developing within the Atlantic Alliance in regard to dealings with the Soviet Union.''
''Never before,'' he asserted, ''have our views been so divergent when considering policy toward our principal adversary.''
On other policy matters - rejection of the proposed Law of the Sea Treaty, the question of arms to Taiwan over Chinese protest, the opposition to aid for the USSR's proposed gas pipe line from Siberia - sharp differences with Western European allies have occurred. In measured, somber tones, Muskie, senator from Maine for almost 22 years before becoming secretary of state under Jimmy Carter, warned a predominantly Democratic group here - the Center for National Policy - of a ''major crisis.''
Speaking July 14, he said there have been differences within the Atlantic Alliance before, ''but never before have our views been so divergent when considering policy toward our principal adversary (the USSR).''
Efforts at closer cooperation with European allies are under way. Reagan has moderated the vocabulary of his attacks on the Soviet Union, which have caused anxiety in Europe. His visit to Europe last month was placatory. Also Secretary of State-designate George P. Shultz may end the savage bickering within the State Department which erupted in Secretary Alexander M. Haig's explosive withdrawal.
Simultaneously European leaders are moving to avert a trade war threatened by farm subsidies, which give their farmers a competitive edge. Leading officials from Common Market countries are now visiting Washington to meet their opposite numbers here, the visit indicating both an awareness of trade difficulties and a desire to do something about it.
Elder statesman Muskie has often stepped forward to answer Republican attacks , from the White House and elsewhere. In the latest instance he did not make an all-out attack but traced various foreign affairs dilemmas to President Reagan. Looking beyond this he urged Israel to leave Lebanon ''with all deliberate speed.'' As to the USSR, he declared unexpectedly, ''We have to recognize that our security is tied to that of the Soviets. We don't want our ultimate fate, and theirs, to be the same - a radioactive ash heap.''
An extraordinary set of differences have suddenly appeared between the Atlantic allies, along with Mr. Reagan's own crisis in the State Department. Some feel President Reagan has modified some of his earlier truculence toward the Soviet Union as global apprehension has mounted over the threat of nuclear war.
But the big test lies just ahead. The US is supposed to begin deploying thermonuclear warheads aimed at the USSR in Western Europe late next year or in 1984. The question rises whether public opinion will allow it.
In a current exposition of the situation, the Wall Street Journal declared July 15 , ''Mounting economic disputes have pushed US relations with Western Europe to their lowest point in recent memory.'' But the disputes aren't just economic.
President Reagan flatly declared on March 31 that the Soviet Union ''does have a definite margin of superiority,'' and has proceeded on a catch-up basis.
He has named two notable hard-liners (Eugene Rostow and Edward Rowny) to carry on disarmament negotiations with the Soviets at Geneva.