Moscow holds its tongue despite souring relations with Islamic Iran

Ties between Moscow and an Islamic Iran it once hoped to woo seem to have soured further since the arrest of top Iranian communists. Contributing to the strain, says a Moscow Middle East specialist interviewed Feb. 22, has been Iran's push into Iraq since rebuffing Baghdad's invasion force in the Gulf war. He also cited various ''anti-Soviet statements'' from Tehran.

Still, Moscow has been limiting itself to words in reply to the detention this month of top Iranian communists. And the Soviet party newspaper Pravda, while sharply criticizing the arrests, adopted a restrained overall tone on future relations.

On the Iran-Iraq front, foreign diplomats confirm reports that Moscow resumed providing military spare parts to Baghdad after Iranian forces crossed into Iraq last year. But the diplomats say deliveries still seem limited.

Most official Soviet news media reports on the war continue to avoid tilting toward either side - but Pravda recently carried a long Iraqi account without an accompanying version from Tehran.

The Mideast analyst interviewed, who stressed he was offering personal opinion, not an inside glimpse of Kremlin plans, said any full-scale tilt toward Iraq in the war, or a similarly radical overhaul of Moscow's tack toward Tehran, was unlikely.

He suggested ties with Iran were likely to continue pretty much on present course: politically, increasingly chilly; in the economic sphere, more ''businesslike.''

A recent sign of the souring relations involves something that didn't occur. Usually the Soviet government newspaper, Izvestiya, marks the Feb. 11 anniversary of Iran's Islamic revolution with an article that is generally positive in tone.

''Given the climate in Iran,'' said the Soviet Mideast analyst, ''how could we possibly . . . print such an article this year?''

He pointed instead to the Feb. 19 Pravda article criticizing the recent arrest in Tehran of senior Iranian communist officials. The article did not mention the Iranian anniversary - intentionally, the analyst made clear.

Meanwhile, other sources say Tehran has moved against Soviet journalists, refusing a visa request from Pravda and telling a Tass reporter his visa would not be renewed.