As Israel's deadline for withdrawing from southern Lebanon approaches, the Palestine Liberation Organization is being squeezed into a sort of no-man's-land between more radical guerrillas who want to step up operations against Israel and Lebanese groups who want to tame such activities once and for all.

In an effort to pacify Lebanese authorities and ensure that the Israelis meet their June 13 deadline for leaving occupied Lebanese territory, the PLO is offering to curtail guerilla activities in southern Lebanon. But radical Palestinian guerilla groups that rejects any moves toward peace with Israel vow to oppose any restrictions on their movements. Rightist Lebanese Christian leaders are pressing demands for further concessions from the Palestinians.

Observers here see yesterday's Israeli raid as making it even more difficult for the PLO to hold back radical factions and promote a more moderate line toward the Lebanese.

The Christian rightists, who fought the Palestinians and their leftist Moslem allies during Lebanon's 1975-76 civil war, want the guerrillas to give up the one thing that even the most moderate refusse to cede their guns.

"We think there is going to be another war," a PLO official explained in an interview. "We don't think the initiative of [Egyptian President Anwar] Sadat will succeed. In these circumstances we are not about to give up our armed presence."

"We want to be able to continue to operate against Israel when the moment arises," he said, "but not directly across the Lebanese border."

The PLO second-in-command, Salah Khalaf, alias Abu Iyad, declared recently that guerrilla attacks would continue from Syria, Jordan and possibly the Sinai in addition to those launched "from our internal bases" in Israel and "by sea." With the exception of southern Lebanon, "we will strike the enemy from every direction," he said.

The Palestinains say they have a right to an armed presence in parts of southern Lebanon under the 1969 "Cairo Agreement," an accord between Lebanon and the PLO so secret that the Lebanese parliament approved it without being informed of its contents.

Rightist Christians, meanwhile, insist that the agreement be abrogated on the grounds that it was superseded by the U.N. Security Council resolution that created the U.N. military force in Lebanon.

After an initial period in which Palestinian guerrillas clashed several times with U.N. troops, PLO leader Yasser Arafat has made an about-face and promised to cooperate with the U.N. mission.

Arafat pledged to stop infiltration by guerrillas behing U.N. lines to positions they occupied before Israeli forces drove them out during the March invasion. At the same time Arafat extended the olive branch to the Lebanese authorities, offering to negotiate, with his Christian foes, pull his armed men out of Beirut and other cities and effectively limit guerrilla activity in the south by banning all "armed manifestations" of Palestinian forces.

Radical Palestinian guerrillas showed what they thought of Arafat's moderate line when they refused to allow U.N. liaison officers into a strategic position the radicals control, the Beaufort Castle on the banks of the Litani River. Arafat had reached agreement with the U.N. commander to station the officers in the castle, which sits on a hilltop and commands a wide field of fire into southern Lebanon.

Given the present squeeze, some political observers see the PLO overtures as busically tactical.

"The PLO is disseminating sweetness and light in all directions so the Israelis won't have any excuse for not withdrawing," one Western diplomat said.

"Afterward it will be the same old story," said another. "The Palestinians will try to get control of the area again."

"The big question, diplomats feel, is whether the expected Palestinian efforts to return to bases in southern Lebanon, notably in the southeastern Arqoub region said to be their preserve under the Cairo accord, will lead to new clashes with U.N. troops or Lebanese army units. The government has promised to send the Lebanese army to the south after the Israeli withdrawal to restore national sovereighty in the area, but no timetable has been set.

Besides the political considerations that dictate the present low PLO profile in southern Lebanon, there is another factor which Palestinian officials are reluctant to admit: The cycle of guerrilla attacks and Israeli reprisals culminating in the widespread destruction of the March invasion has turned even the Moslem population against the Palestinian fighters.

"The people hate us down there," one PLO official acknowledged. "They can't stand the sight of us."

This kind of rejection from quarters that had previously supported the guerrillas could be responsible as much as anything else for the PLO decision to curtail operations in the area, according to diplomats.

All this does not mean the PLO is abandoning the overall fight against Israel. On the contrary, it is emphasizing more and fiercer attacks by guerrillas in the occupiedl West Bank and in Israel proper, such as the Jerusalem bus boming last week which killed six people and wounded 20.

"We're not going to roll over and play dead just because the U.S. wants us to be moderate," a PLO source said. "We have to do nasty things like this or nobody would pay any attention to us."