Beirut — The blond Israeli soldier leaned back against the railing along the waterfront, the curve of war-battered buildings around the shoreline visible for miles behind him.
''After we cleaned all Lebanon from terrorists, the Lebanese say now they don't need us. Now they tell us to leave Lebanon,'' he remarked ruefully.
His companion, like him a regular Army officer trainee in the paratroops, demurred sharply.
''(Lebanese President) Amin Gemayel won't tell us to get out,'' he insisted. ''He needs us. He knows if Tzahal (the Israeli Defense Forces) go, he'll have many problems.''
After invading west Beirut a week ago, Israel Sept. 23 was preparing to leave. Israeli troops were thinning out their positions and handing them over to the Lebanese Army in an operation that Israeli spokesmen say will be completed on Sunday.
Their stay has left many Israeli soldiers shocked by a culture and a people whom they do not understand. Some are also uncertain about what they have achieved.
Much the same bewilderment and concern were very evident also within Israel itself Sept. 23. And Prime Minister Menachem Begin - assailed by parliamentary critics, by segments of the press, by messages from American Jewry, and by more planned demonstrations and protests - was trying to rebuild his administration after Wednesday's resignations.
Meanwhile, as Israel continued its pullback, the first units of the 3,000-man American, French, and Italian multinational force arrived Thursday to try to buffer Beirut against any repeat of last week's massacre of Palestinians in their refugee camps in Beirut's southern suburbs. Red Cross officials pushed ahead with their efforts to recover bodies from the rubble of the camps, with some 300 dead found by Wednesday night and many more thought so far undiscovered.
It was to this background that the new Lebanese President, Amin Gemayel, was inaugurated - and appeared to turn away from an alliance with Israel toward closer ties with ''our brother Arabs'' and the United States. Mr. Gemayel stressed his wish for immediate withdrawal of all foreign forces from Lebanon to ensure his government's sovereignty.
But as he spoke, Israeli troops could still be seen in pockets throughout the city, sitting on tanks in front of former offices of the Palestine Liberation Organization; relaxing on the porch of a waterfront hotel that was once a Lebanese leftist headquarters; sunning themselves by the seaside; or - occasionally - strolling in small groups down west Beirut's once chic but now badly damaged Hamra Street.
Some of the soldiers seemed to take their presence in this former PLO bastion , chipped and blackened by Israeli shells, with ease.
''Don't be afraid to say out loud you are from Jerusalem,'' one soldier in civilian clothes and close-fitting Israeli kibbutz hat advised another on Hamra Street.
Others were more aware of the strangeness of their presence in an area that only days ago was under Israeli siege. West Beirut residents stared quietly but did not greet Israeli soldiers with the warmth shown by east Beirut Christians.
''It's bizarre to be here, Fellini-esque,'' said one Israeli officer on the steps of the Commodore Hotel, where PLO officials once rendezvoused with foreign journalists.
But many soldiers were bewildered by the complex internal feuding within Lebanon that underlay the massacre by Christian militiamen of Palestinians in the camps of Sabra and Shatila. Of a dozen soldiers interviewed, none of whom were directly involved in the camp incidents, not one believed Israel was directly responsible for the massacre. But most expressed scorn or amazement at the actions of the Christian militiamen - actions that would not be surprising to anyone familiar with the traditions of revenge so prevalent in Lebanon.
''We let the Christians in to kill terrorists; we never thought they would kill children,'' said Benni, a paratrooper from Ashdod.
Itamar, a young private with spectacles, added angrily, ''All during the war in Lebanon we expected the Christians to fight with us and they didn't. They just know how to talk and to kill unarmed civilians.''
But a curly-haired Jerusalemite soldier named Mikhail added quietly, ''The Phlangists (Christian militiamen) are the 'black soldiers' for Israel. We didn't want to lose our men in the camps.''
Israel's justification of its invasion of west Beirut was to root out 2,000 armed PLO men whom they say stayed behind after the PLO left - a claim disputed by the US State Department. Hundreds of Beirut residents living outside the camps have been questioned but no one - not even the International Committee for the Red Cross - has a figure for those still being held.
Israel is also collecting arms from caches left by PLO and Lebanese leftists. Throughout the city Israeli soldiers with trucks and flatbeds can be seen collecting boxes of ammunition and heavy weapons from schools, apartments, and mosque basements where they were stored. Israel says it will continue to search for arms in west Beirut areas from which it has withdrawn.
Scores of trucks deliver loads of these arms to Israel daily. Some have been given to the Lebanese Army and to the Christian militias. One such load exploded , apparently accidentally, in east Beirut during Mr. Gemayel's inauguration.
Israeli soldiers can also be seen searching for documents, carting out books, archives, and manuscripts from the PLO's Palestinian Research Center, according to reliable Lebanese sources. Beirut residents whose names were found on subscriber lists were being questioned. Israeli soldiers also visited the Bank of Syria and Lebanon with photocopy machines.
For most Israeli soldiers participating there is little questioning of their job.
''We have to do this, to help Lebanon to have a strong government,'' says Benni, a private from Netanya, standing by the seaside railing. ''We have to make sure the PLO can't come back.'' But some soldiers are unhappy about the actions of Defense Minister Ariel Sharon.
''We shouldn't be here; I'm going back to the United States and study until Sharon resigns,'' said one recent emigrant from the US now sitting on a tank near a former PLO office.
Added Mikhail, the soldier from Jerusalem, ''At the rate we are going, we will have to keep chasing the PLO to Turkey. I hope we just get out of here.''