Does Israel -- or Iran -- worry the Arabs most?

The Islamic Republic of Iran has so far shown an incredible capability of overcoming internal and external threats. It now has the upper hand in the war with Iraq and appears more and more willing to export its revolution abroad.

That frightens the ruling families on the south shore of the Gulf: every victory of the Iranian troops has tremendous impact on their people, especially on the important Shiite minorities. Travelers coming back from the Gulf area report that the prestige of Ayatollah Khomeini is increasing every day and that one of the biggest mistakes of the local governments has been to depict the Iranian mullahs as crazy fellows whose regime would capsize within a few months. Today the reemergence of a powerful Iran appears to many as a sign of God's will.

Conservative Arab governments, which at first refrained from openly criticizing Iran while discreetly backing Iraq, now are loudly attacking the regime of Ayatollah Khomeini.

The Emirates, mainly Kuwait, are actively helping Iraq in its war effort. Wounded Iraqi soldiers are treated in Kuwaiti hospitals and Kuwaiti ports are congested with ships unloading all kinds of goods, including weapons, destined for Iraq. This is why Iranian jet fighters have already attacked the Iraqi-Kuwaiti main border post three times.

The Emirates and Saudi Arabia have also granted huge loans to Iraq, which enables the Iranians to claim that ''the Arabs spend more money to fight our revolution than they ever spent to fight Israel.'' The Saudis, who have always considered themselves custodians of the Emirates' independence and integrity, are more and more anxious. They are also exasperated by Radio Tehran's newcasts which report, most of the time with accuracy, every single political incident happening in Saudi Arabia.

Last December the Saudis convinced the rulers of the Arab Gulf states to sign a defensive alliance. This has infuriated the Iranians. ''The Arabs should know that we are the most powerful country in that area and that our navy remains untouched,'' Iranian President Ali Khamenei said recently.

Evidence of how nervous the conservative rulers of the Arabian Peninsula are can be found in the communiques they issue at the end of their numerous meetings. They talk less and less of ''the fight against Zionism,'' prefering the expression ''matters that are related to the security of the Gulf.''

King Hussein of Jordan also is uneasy about the inefficiency of the Iraqi Army and recently decided to send troops to the war front. ''If Iraq falls,'' he said, ''there will be all sorts of dangers.'' Diplomats in Amman believe that the recent renewal of Jordan's verbal aggressiveness toward Israel is in fact an answer to PLO officials who have blamed King Hussein for diverting his attention from Israel toward the Gulf.

The center of crisis in the Middle East is thus slowly slipping to the east and in the next years the Gulf question could overshadow the Israeli issue. Seen against this perspective, the AWACS soon to be delivered to Saudi Arabia will probably be more useful in monitoring Iranian than Israeli aircraft.

The Israelis, well aware of this geopolitical evolution of the Middle East, are doing their utmost to stir up rivalries between Iran and its Arab neighbors. Prime Minister Menachem Begin understands that a major Israeli drive into southern Lebanon would catch the Arab countries unprepared but it would also give the Islamic world an occasion to reunite, at least temporarily. Although recent protests in the Israeli-occupied West Bank have again put the Palestinian question in the spotlight, the Arabs are discovering that it is very difficult to keep their attention focused on two problems at the same time.