Washington — State Department officials would welcome Soviet backing for a dialogue between the Polish authorities and the Solidarity trade union movement. But some officials are skeptical of the moderate tone taken by a senior Soviet official on this subject in a talk with the Monitor's Moscow correspondent Ned Temko. The senior Soviet official said that the success of martial law would depend partly on a dialogue with Solidarity and that the union movement would necessarily be a factor in renewed efforts for political entente in Poland.
''If the Soviets really put their weight behind a dialogue, that would be welcome,'' said one State Department official.
But the official also said he was not convinced that the Soviets were indeed supporting such a dialogue wholeheartedly.
The official said that the Soviets were ''highly skilled'' at orchestrating their public and private statements on several tracks. A moderate-sounding statement to an American reporter, he said, might ''help to defuse the efforts of those in the West who would like for our government to pursue a harder line'' toward the Soviet Union as well as toward the Polish authorities.
One non-government expert, Abe Brumberg, former editor of the journal ''Problems of Communism,'' says that Soviet press attacks on Solidarity had not been conducive to a dialogue and indeed only encouraged an atmosphere of conflict.
At the same time, Brumberg has believed from the beginning that the Soviets were extremely reluctant to mount an invasion of Poland for fear of the ''enormous political, economic, and military price which they would have to pay.'