Soviet Foreign Minister Andrei Gromyko arrived in Damascus, Syria, today for a three-day visit designed to reaffirm relations between the increasingly isolated Soviet and Syrian governments.

Gromyko's visit was the first to the Middle East by a major Soviet figure since the Red Army invaded Afghanistan a month ago and incurred the wrath of the overwhelming majority of Islamic states.

His sojourn signaled probable new arms deliveries to a Syrian government that is under increasing attack at home and feeling naked in the face of a heavily armed Israel strengthened by its separate peace with Egypt.

Syria's helplessness has been underlined by the reactivation of a long-running feud with its Baath socialist rival and neighbor, Iraq -- a quarrel that had been temporarily shelved at the end of 1978 out of shared opposition to the U.S.-sponsored Camp David accords between Egypt and Israel. This renewed distraction on the country's eastern flank has further weakened the country's defensive capability, as has the maintenance of the 30,000 Syrian troops that have been bogged down to the west in Lebanon for the past 3 1/2 years.

Indicative of President Hafez Assad's domestic problems were the embarrassing recent assassinations of two Soviet colonels in the central Syrian city of Hama and the bombing of the Damascus office of the Soviet airline Aeroflot.

After nine years in power, the government, which relies on the minority Alawite Moslem community for its survival, has come under increasing attack with political assassinations a regular occurrence. The government has blamed the fundamentalist Moslem Brotherhood for the attacks.

Symptomatic of Syria's diplomatic problems was its apparently eroding leadership of the so-called "Steadfastness Front" founded in 1977 to prevent Egypt from deserting the Middle East military equation and signing a separate peace with Israel.

Syria refused to attend the Islamic conference that opened today in Islamabad, Pakistan, to discuss the Soviet invasion of Afghanistan. But only Marxist South Yemen among Damascus' four partners in the front stuck to their earlier decision to boycott the meeting.

Algeria and Libya sent delegates to Islamabad, and the Palestine Liberation Organization finally announced its resident representative in Pakistan would attend as an observer.

Assad apparently tried to moderate the anti-Soviet feelings of conservative Moslems in a 24-hour visit to Riyadh, Saudi Arabia, where he conferred with King Khalid and other Saudi leaders before flying back to Damascus to meet Gromyko.

Saudi Arabia, whose Crown Prince Fahd was quoted as favoring establishing diplomatic relations with the Soviets just two days before the Afghan invasion, is in the vanguard of the Kremlin's critics at Islamabad despite radical Arab efforts to include condemnation of U.S., Egyptian and Israeli policy in the Middle East.

Despite Syria's isolation, Assad was not expected to sign a friendship treaty with the Soviet Union such as those in force between the Kremlin and Iraq and Moscow and South Yemen.

As if to underline Syrian ties with the West, Foreign Minister Abdel Halim Khaddam, who greeted Gromyko today in Assad's absence at mid-day, is scheduled to visit France starting Tuesday.