Syria gains new power in Mideast as its noose tightens on Arafat

PLO chief Yasser Arafat appears to be taking his last stand, fighting for life and leadership against Syrian-backed rebels closing in on his last stronghold.

The four-day offensive on two Palestinian camps - Nahr Al-Bared and Baddawi - on the outskirts of the northern Lebanese city of Tripoli seems to be the final phase of a six-month mutiny. Dissidents within Mr. Arafat's Al-Fatah faction are near success in their bid to change the organization's leadership and strategy.

On Sunday, Arafat ordered his fighters to abandon Nahr Al-Bared. It was a major blow, although the majority of PLO forces have long been concentrated in Baddawi.

Casualty reports vary wildly. Already at least 145 are reported dead and 500 wounded, most of whom are Lebanese and Palestinian civilians, say international relief agencies.

The man who transformed the Palestine Liberation Organization from an ineffectual mixture of ragtag fighters and intellectuals into a sophisticated and well-armed organization during his 15-year rule has little hope of winning this round. He and some 8,000 loyalists are outgunned and outnumbered by rebels and, more importantly, Syrian troops.

Arafat is now an embattled and abandoned figure. In the same breath he makes bold pledges to ''fight irrespective of the odds'' while issuing desperate appeals to Arab and Islamic leaders to intervene.

The open participation of Syria in this final phase has made all the difference, say Western military analysts. They doubt the rebels, led by Abu Musa, could accomplish the job alone.

Although Damascus has vigorously denied its involvement in the past, despite visible proof to the contrary, its admitted role now seems to back up what Arafat has been claiming all along: that President Hafez Assad wants the fiercely independent Palestinians under his control.

Having the PLO under his thumb would put Mr. Assad in the spotlight during any future negotiations on a broader Mideast peace centered on the Palestinian homeland issue. One of the Arab world's most militant leaders would become de facto the primary negotiator on the Arab side, stealing the role from moderate King Hussein of Jordan, whom the US had hoped would be the channel to peace.

Diplomats here feel the timing of the new offensive, which overlaps with Lebanese reconciliation efforts, is not a coincidence. Influential moderate Arab states, such as Saudi Arabia, that have tried to intervene on Arafat's behalf are now preoccupied with the Lebanese crisis - in which Syria again holds the trump cards. No Arab state has sufficient leverage to pressure Assad on both issues.

An Arab League summit is also tentatively scheduled for later this month in Saudi Arabia. Arab envoys claim Damascus wants to be able to present an alternative PLO leadership then with no possibility of dissension, that is, with Arafat officially out of the way.

Another factor is the weather. Winter snows in mountainous northern Lebanon would make movement of troops and heavy equipment difficult, giving guerrilla bands an advantage. Syrian supply lines might also be cut off.

Arafat has indeed laid the blame on Syria: ''They're attacking us from all directions. . . . We shall die hard.''

The PLO chief has long been predicting this final squeeze. He snuck back into Tripoli two months ago after being banished from the area by Syria in June. He and his forces have effectively been under siege in Tripoli since then.

Only two Arab states - Jordan and Saudi Arabia - have come to his aid recently, with appeals for a cease-fire. But they were little more than hollow words, since the mutiny had gone too far for any action, short of armed intervention, to be of help.

Yet it may not be a fast fight. As with the prolonged Israeli siege of Beirut last year, the PLO loyalists could make it difficult for total penetration of Tripoli's urban areas by a conventional army, at a high cost in human lives, according to military analysts.

Syrian forces have now blocked off the major access routes. Rescue workers report massive shortages of water, food, and electricity. Ironically, these are the same tactics the Israelis successfully used to force Arafat out of another part of Lebanon last year.