In a joint communique on their new 20-year treaty of friendship and cooperation, the Soviet Union and Syria made no mention of the Iraqi-Iranian war next door to both countries, and instead praised the Iranian revolution.

The two sides added, in what was a clear attempt to curb Iraq, that Damascus and Moscow "support the inalienable right of Iran to decide its destiny independently without any interference from outside."

The communique, issued several hours after Syrian President Hafez Assad left the Soviet Union at the completion of three days of talks, underscored the Kremlin's embarrassment at the Persian Gulf war. Under its 1972 friendship pact with Iraq, Moscow is sending arms to Baghdad that the Iraqis are using to make war on their fellow Moslems in Iran. The Kremlin has sought to establish good relations with the government of Ayatollah Ruhollah Khomeini since the shah was toppled almost two years ago. But the Soviets have had little success, and the Iraqi thrusts across the Shatt-al-Arab waterway into Iran have not helped Moscow.

The Syrians and Soviets "reaffirmed" their commitment to a "joint struggle for achieving an all-embracing Middle East settlement" based on unconditional withdrawal of Israeli troops from all Arab territories taken in the 1967 war, and "implementation of national rights of the Palestinians" including self-determination and a homeland.

Moscow seemed to have ended all significant differences with Assad over the Syrian intervention into the Lebanese civil war. The communique asserted that the two capitals jointly support "strengthening the lawful power of the Lebanese government and the observance of the legitimate interests of the Palestinian resistance movement in Lebanon."

But it was the lack of any mention of the Iraqi-Iranian war, the biggest crisis in the area in recent years, which caught more foreign attention here. The Soviets have officially said they are neutral and called for Baghdad and Tehran to negotiate their dispute. But the implied censure of Iraq is seen here as a rebuff to Iraqi leader Saddam Hussein demanded by Assad, who despises the Baghdad strongman and envies him his seeming regional image of strength.