The election of right-wing Christian militia leader Bashir Gemayel as president of Lebanon will propel the young warlord into Lebanon's center stage while apparently strengthening the hand of the Christians in this war-torn country.
But the election, boycotted by most of Lebanon's Muslim deputies, has aroused fear among religious leaders of the Sunni, Shiite, and Druze Muslim sects that the delicate balance between the Christians and Muslims in Lebanon may soon be shattered.
Many Muslims have bitter memories of Mr. Gemayel's role in leading the Christian militia in this country's bloody 1975-76 civil war. In addition, Mr. Gemayel's forces have cooperated with the Israeli Army and in the past have received guns, ammunition, and tanks from Israel.
An effort in the parliament to postpone the election and agree on a compromise candidate failed. Instead, Mr. Gemayel was elected in the second balloting after the 92-seat body achieved a quorum. He received 57 votes.
It remains to be seen whether Mr. Gemayel will be able to heal the rifts between the Christians and Muslims, leftists and rightists that have torn Lebanon apart in the past decade. But his election, combined with the evacuation of the Palestinian guerrillas from Beirut and the continued Israeli military presence in the country, seems sure to give the Maronite Christians the upper hand in the coming weeks.
The evacuation of the PLO guerrillas will greatly weaken the leftist, Muslim militias of west Beirut. Grouped under the banner of the National Movement, these militias have been aided extensively by the PLO since the early 1970s. In fact, as the PLO has begun leaving Beirut, it has handed over large amounts of war material to the Nasserite Muribitoun. Even so, the leftists will be hard pressed now to hold out against the Phalange, especially since the Phalange is aided by the Israeli Army.
One of the uses of the 2,000-man multinational force in the next month will be to help interpose the Lebanese Army between the Phalange and the Lebanese leftists. This may be rather difficult, however, since the leftists see the Lebanese Army as Phalange-infiltrated. The multinational force's mandate ends around Sept. 28, and diplomats hope that some peaceful accommodation between right and left can be made by then.
Mr. Gemayel is expected to try to merge his well-disciplined Phalange militia with the divided and relatively ineffective Lebanese regular Army.
The Phalange has given extensive aid to Israel in its invasion of Lebanon. In turn, Israel appears set to help Mr. Gemayel consolidate his hold on the country and drive out the remaining Syrian and Palestinian forces.
Although the political balance in Lebanon will tip to the right with a Phalange-oriented president, one hears Lebanese of all ethnic and religious backgrounds endorsing Mr. Gemayel - or the discipline he seems to stand for.
''It will be hard. . .,'' a Lebanese woman says, ''but Lebanon today needs discipline.''
''Everybody wants to go out at night in Lebanon, and it may take Bashir to give us that kind of security,'' a Lebanese newspaper editor says.
Others, however, anticipate a wave of rightist-leftist fighting in the next months and say the Phalange will be vindictive if it takes control.
Meanwhile, an estimated 500 Palestinian guerrillas departed for South Yemen, and approximately 1,000 others were preparing to leave Aug. 24 for North Yemen as part of the evacuation plan negotiated by United States envoy Philip C. Habib.
During the weekend approximately 1,400 guerrillas departed for Jordan, Iraq, and Tunisia in the first stages of the evacuation.
The plan calls for the departure of up to 15,000 Palestine Liberation Organization and Syrian fighters from Beirut during a two-week period ending Sept. 3.
The early stages of the evacuation are being supervised by French Legionnaires, who will be joined in their peacekeeping role later this week by American and Italian troops.
The Habib plan does not address the departure of Syrian and Palestinian forces located in northern Lebanon and the eastern Bekaa Valley. An estimated 30 ,000 Syrian troops and several thousand Palestinian fighters are reported to be digging in there.
Reports indicate the Syrians have reinforced their lines with men, arms, and 400 tanks. The Israelis have reportedly reinforced their lines in central Lebanon with an additional 220 tanks.
Israeli officials have expressed concern that tension in the Bekaa Valley could flare into a new round of fighting unless Syria prevents Palestinians from launching hit-and-run operations against the Israelis.
''We do not want a new war. . . . But if they (the guerrillas) don't stop it, we will have to do something,'' said a senior Israeli official.
The statement came after the Israelis announced that three guerrillas were killed when they tried to infiltrate to Israeli lines near the Bekaa village of Aammiq and one Israeli soldier died from wounds received in a skirmish the day before.
Another five Israeli soldiers were wounded in an ambush near Tyre, the Israelis said.
Israel has told Washington that Israel will not tolerate cease-fire violations from Syrian-controlled areas.