DHAHRAN, SAUDI ARABIA, SEPT. 2 -- Western and Saudi analysts here are predicting that Iraq's invasion of Kuwait will consummate one of the Arab world's most unusual alignments in decades, bringing Syria, Saudi Arabia and Egypt into a potentially powerful political and military alliance against Iraqi President Saddam Hussein.

"Iraq's imperial ambitions have brought them together," said one Western diplomat.

He said the emerging three-way alliance contained the seeds for a new Arab containment policy toward Iraq that, if successful, could lessen the need for a permanent American military presence in the Persian Gulf.

One of the most unexpected consequences of Saddam's action has been Syrian President Hafez Assad's decision to send elite special forces troops to help defend Saudi Arabia -- a onetime radical, still secular Arab regime coming to the rescue of an ultra-conservative Islamic monarchy.

The Syrians' presence here has been the talk of the kingdom, although they seem somewhat embarrassed. Western reporters have been barred from visiting Syrian troops, and the Saudi state-controlled news media have given them little publicity. A promised address by the commander of the Syrian forces has yet to be aired on Saudi television and radio.

Nonetheless, the fact that Syrian troops are here says a lot about the distance Assad has come in the last year toward the camp of the two most pro-American Arab states in the region and reflects how isolated the Syrian leader must feel he has become in the kaleidoscope of Arab politics.

Western diplomats here have long regarded Saudi Arabia and Egypt as natural partners, matching Saudi oil and financial wealth with Egyptian military strength and manpower. Egyptian President Hosni Mubarak and Saudi King Fahd have cooperated for several years on such matters as Arab League politics and gulf security issues.

The current crisis has brought them even closer together. Egypt has sent at least 2,000 commandos and is said to have offered as many as 30,000 troops as part of a multinational Arab-Islamic force to help defend Saudi Arabia against the Iraqi threat.

Saudi Arabia, in return, has sent Cairo $175 million in the last two weeks, ostensibly to help the Egyptian government cope with the flood of Egyptians returning from Iraq and Kuwait.

"One lasting effect of the current crisis will be the consolidation of the Saudi-Egyptian relationship," predicted a diplomat.

The two governments are even discussing building a bridge across the Gulf of Aqaba, about eight miles across at its narrowest point, to connect their countries. Fahd has personally pressed the project despite the reservations of his advisers, according to diplomatic sources.

Mubarak has been instrumental in bringing Assad in from the radical cold. It started with a makeup handshake at the Arab League summit meeting in Casablanca in May 1989. In December, the two nations restored diplomatic relations after a 12-year break -- and air links between the two capitals. Mubarak and Assad exchanged visits in May and July.

Western diplomats here say they believe Assad has varied motives for moving so decisively toward Cairo and Riyadh. These include his need for Saudi financial aid, a replacement for his fading relationship with the Soviet Union and his search for Arab partners to counter Saddam's growing power.

Assad and Saddam head rival wings of the Arab Baath (Renaissance) Party and are sworn enemies. Whether the Cairo-Riyadh-Damascus triangle will solidify, as Western diplomats here ardently hope, is too early to judge, based on past abrupt changes in many Arab alliances.

Egypt was a partner with Iraq, Jordan and Yemen in the Arab Economic Council but now has lined up solidly with Saudi Arabia against Iraq. Jordan, until Aug. 2, was on good terms with Egypt and Saudi Arabia, but now that it has come out in support of Saddam, Jordan's King Hussein is being cursed here as a "political prostitute."

One possibility that might upset the emerging Saudi-Egyptian-Syrian alliance would be a decision by Saddam to attack both Israel and Saudi Arabia, as he threatened recently. Such a move could start an Arab-Israeli conflict as well as one between Iraq and the United States.

Assad might then find being on the same side as the United States and Israel in a war against Iraq more than he could tolerate politically, since he has long prided himself on being Israel's main Arab foe.

This scenario conjures up such a nightmare of confusion in Arab politics that Saudi leaders simply refuse to discuss it. Such "hypothetical" questions involve too many "ifs, ands and buts" to answer, said Lt. Gen. Khalid bin Sultan, commander of the combined Arab-Islamic forces.