While seeking to exploit the Iranian-Iraqi conflict to expand Soviet influence as widely as possible in the Middle East, the Kremlin is encountering complications in the region that are likely to limit its success.

The increasingly complex situation is believed to have been the reason for the unexpected postponement of the long-scheduled visit here by Jordan's King Hussein. Diplomatic observers here believe the postponement was requested by Moscow, which apparently feared a faceoff with Hussein on the question of expanded arms deliveries to Iraq.

The main thrust of Soviet policy appears to be an effort to gain a foothold in Iran while avoiding a split with Iraq, with which Moscow has a 20-year friendship and cooperation treaty.

Moscow has tacitly approved Hussein's leap to the Iraqi cause. Officials believe it offers future gains for Soviet Middle East strategy at the expense of the United States, Egypt and Israel. Moreover, Soviet ships have been using the Jordanian port of Aqaba to unload shipments destined for Iraq and sent there by land routes.

[In Tokyo, and Iraqi Cabinet minister denied that his country was receiving Soviet military supplies through Jordan, Reuter reported. "We have not asked the Soviet Union to resupply us," Jassem Mohammed Khalaf said. Khalaf is minister of higher education in the Iraqi government.]

The possibility that King Hussein might raise the issue of expanded arms deliveries to Iraq contained risks for Moscow. The Soviets had the choice of either rebuffing Hussein or risking further deterioration in their already poor relations with Iran.They have finessed the dilemma by putting off the visit, according to political observers here.

This move comes in the wake of the signing of a Soviet-Syrian friendship and cooperation treaty. Syria, an archrival of Iraq, has endorsed openly the Iranian cause in the Gulf war.

As a result, Moscow seems deeply embroiled in the inconsistences of the Middle East, entering into alliances with bitter mutual enemies in a clear effort to gain positions in the area irrespective of the outcome of the current conflict.

At the same time, the Kremlin is deeply worried about the steady buildup of Western naval forces in the Arabian Sea and Indian Ocean. There are no doubts here, as daily Soviet press warnings suggest, that the United States intends to use force to keep the Strait of Hormuz open should the Iranians attempt to stop the flow of oil out of the Persian Gulf. Few here seem reasurred by Tehran's statements that it will not interfere with oil shipping through the strait.

While forecasting such a move in alarmist tones, Moscow at the same time understands the problems confronting Washington. Analysis in the foreign affairs weekly New Times put the problem in these terms:

"If the United States comes out against Iran, it will immediately call into question the destiny of the hostages. And an anti-Iraq stand [by Washington] would touch off a wave of protests from all Arab states and inevitable oil sanctions, whose consequences cannot even be imagined."

It is a striking passage because, perhaps inadvertently, it also makes clear Moscow's own stake in the conflict.