The reappearance of Syrian soldiers in the streets of this battered and crime-ridden city for the first time since 1982 has coincided with a craving for order and tranquility by ordinary citizens.

After two years of increasing deterioration, with a flight of foreigners, embassies and teachers, there is a reservoir of good will for anyone bold enough to come to the Lebanese capital with the intention of restoring calm.

"We just hope that what is starting out as a cosmetic job for Beirut does not end up hurting us," one worried shop owner said, recalling past unpleasant experiences that Lebanon's various factions have had with Syrian forces. But residents say this time the Syrian soldiers have been on their good behavior.

Analysts say, however, that it is not clear why Syria chose this moment to brave the chaos of Beirut, although they mention oft-cited theories of outside conspiracies: secret deals with the United States or other western countries over hostages, or with Israel over security arrangements in southern Lebanon.

The Syrian troops' arrival surprised city residents. But regardless of whether their return surprised anyone else, or was given the green light by Washington or others, no one has objected -- except Palestine Liberation Organization chief Yasser Arafat, who fears a final showdown between his loyalists and Syrian troops.

Brig. Ghazi Kanaan, chief of Syrian military intelligence in Lebanon, and a trusted emissary of Syrian President Hafez Assad, described the mission of Syrian special forces and plainclothesmen here as "surveillance." He noted guardedly that "efforts are under way for the release of the hostages. Appeals are being made to all sides to bring their detention to an end. There is sincere concern, but we don't have all the data."

Pressed on whether Syrian troops would deploy in the Shiite-dominated southern suburbs of Beirut, where some hostages are believed to be held, Kanaan replied elliptically that it is really the regular Lebanese Army soldiers and police who are in charge of west Beirut's latest security plan.

"We are just here for moral support. They have the substantial role of maintaining law and order," he said in an interview. "But I am here, with a stick in my hand which I am holding behind my back for the moment. I will brandish it and know how to use it when the need arises."

Kanaan, who is being entertained nightly at the homes of wealthy Beirut residents hungry for a minimum of security and stability, said the storming of fundamentalist hideouts was risky. "The safety of hostages is paramount. Any such operation may endanger their lives," he said.

Nonetheless, he said, "we are hoping for the best because there is serious interest in the fate of the hostages. This has become a humanitarian question. There is no advantage to anyone in their captivity."

The number of Syrian special forces here has been estimated at 200 to 300. Kanaan said those estimates are exaggerated but he would give no figures. In addition, Syrian intelligence agents in civilian clothing appear to be everywhere.

The Syrian military presence has impressed militiamen, squatters and sidewalk vendors -- who had cleared off the streets. Even garbage collectors, awed by the few helmeted Syrians accompanying Lebanese troops, are working again after months of neglect. Bearded militiamen who in the past paraded freely with their weapons, have put away their guns and shaved.

Syria's motives for pacifying Beirut appear to be two-fold, according to analysts: to tighten control over Palestinian camps, where Arafat is still an uncontested leader and to clamp down on extremist Iranian-linked groups, since Syria has come under fire from the West for harboring terrorists and allowing them to operate freely in Lebanon.

The Iranian-backed Hezbollah faction has publicly expressed support for the new security plan, but it is said to be on alert in its areas and not pleased with the prospect of a possible Syrian sweep over them.

While Arafat, who appears to be the biggest loser in the new arrangement of forces, harshly attacked it, accusing Iran and Syria of striking a deal aimed at wiping out Palestinian refugee camps in Beirut, the response of Lebanon's Christians has been mixed.

Former president Camille Chamoun, 85, a longtime leader of the Christian community, initially gave Syria's return a guarded welcome, saying if it meant an end to militia wars in west Beirut or the start of peace for Lebanon it was "not bad."

But Friday he joined Christian militia commander Samir Geagea, Phalange Party leader George Saade and other Christian figures in denouncing the way in which Syrian troops had returned. They charged that Syria had violated Lebanon's "national sovereignty" and had not sought approval of the government or Army command, both of which are heavily Christian.

President Amin Gemayel, despite initial protestations as to the legality of the Syrian deployment and Damascus' failure to notify him in advance, told visitors Wednesday that he was not against the return of security to west Beirut or any other region. "We cannot live without cooperation with Syria," Gemayel, a Christian, told a group of Lebanese legislators, according to one of those present. "Syria has a natural role here and we have always placed our bets on good, normal and solid ties with it."

While Lebanese living in Christian-controlled areas have become largely indifferent to what happens in Moslem west Beirut, they say they are concerned that Syria's moves could engulf their own east Beirut later.

"Right now we find it difficult to criticize any attempt at restoring order in west Beirut, but I know one thing: I would not like to see Syrian soldiers in my neighborhood," said a prominent Christian banker, recalling 1978, when Syrian troops besieged Christian east Beirut, shelling it from artillery sites in Moslem regions.