Prime Minister Menachem Begin has decided not to summarily brush aside American diplomatic efforts to lower tensions between Israel and the Palestine Liberation Organization (PLO).
He has agreed to permit special US envoy Philip C. Habib to hold talks with the Lebanese government to bring about a cease-fire along the Lebanese border following devastating Israeli air attacks on Lebanon.
The concession falls far short of what the Reagan administration had clearly hoped the Habib mission would bring: a limited cease-fire while the US envoy was still in Israel.
Despite encouragement by Israel to Mr. Habib to continue his mediation efforts, obstacles to achieving even a breather in the Israel-PLO cross fire remain formidable:
* The fact that Lebanon hasn't the muscle to control the PLO in its own country means that it is highly unlikely that the Habib mission to Lebanon will succeed in bringing about a cease-fire.
* Israel has hinted it would not refrain from military attacks in Lebanon while Mr. Habib is trying to bring about a cease-fire, should the PLO continue to shell Israeli towns.
In fact, within hours of a secret Israeli Cabinet decision on a US demand for a cease-fire, Israeli jets struck at south Lebanon again July 21. At the United Nations, the UN Security Council was summoned into session July 21 amid reports it might set a 72-hour deadline for a halt to the Lebanon fighting.
* Mr. Habib's negotiating task is complicated by Mr. Begin's insistence that Israel will under no circumstances hold conversations directly or indirectly with the Lebanon-based Palestine Liberation Organization, with whom they have been exchanging escalating military strikes over the past two weeks.
During a marathon five-hour Cabinet session, Israeli ministers reportedly expressed reservations about agreeing to a cease-fire before a broader solution was reached to the problem of PLO attacks across Israel's northern border.
At the same time they were aware of US anxieties to deescalate the Israeli-PLO violence and American displeasure about an Israeli bombing raid that caused hundreds of civilian casualties in Beirut.
Israeli officials have angrily rejected any linkage between the earlier intention to deliver US F-16 fighter planes and the "indefinite" suspension ordered July 20 after Israeli air raids over Lebanon. US officials have denied such linkage exists, saying only it was "inappropriate" to send the planes at this time.
A US-negotiated cease-fire between Israel and the PLO, even if it is arranged via Arab third parties ordered to honor Israel's refusal to deal with the PLO, will boost the PLO's international political standing. And Israel will be reluctant to accept a cease-fire that does not halt the flow of heavy weapons they say is reaching the PLO from Syria, Libya, and the Soviet bloc.
Israeli officials have said that they want the Lebanese government to remove PLO bases entirely from Lebanon before Israel considers a cease-fire.
But, given the paralysis of Lebanon's central government, which lost control over the PLO back in 1969, this is clearly impossible. Moreover, the Syrians, who dominate Lebanon militarily, are unlikely to rein in their PLO ally under heavy Israeli military pressure.
Israel has left open the possibility of returning to a stiff military posture against the PLO should Mr. Habib's negotiations fail. Israel's policy of the last two weeks -- massive air strikes against PLO bases, infrastructure, and offices without concern for civilian casualties -- represents a shift from the Israeli policy, in effect since April 1980, of selective preemptive strikes by land, sea, and air against PLO bases in Lebanon. In 1978 Israeli ground forces invaded south Lebanon but withdrew under international pressure and were replaced by a United Nations buffer force and by Christian militias allied to Israel.
Military analysts here say, however, that there was pressure within the Israeli military establishment for some time to "clean out" PLO bases entirely from south Lebanon. In an interview published in the Israeli press in April 1981, Chief of Staff Rafael Eitan said, speaking of anti-PLO military policy, "One day a blow will come . . . and the entire terrorist [PLO] deployment in Lebanon will fall apart. Such a possibility can come about quickly."
The PLO's recent heavy rearmament apparently provided the raison d'etre for the shift in policy. And the PLO's heavy rocket shelling of Israeli border settlements, in response to Israeli air strikes, gave the Israeli government strong domestic backing for its subsequent attack into Lebanon.
However, news media and Labor Party opposition critics have begun questioning the government's thesis that massive bombing raids on PLO bases and infrastructure can halt PLO attacks. Leading military figures, including Israel's chief of military intelligence and its deputy defense minister, have admitted that mobile rocket launchers cannot be totally knocked out by bombers.
Former Labor Prime Minister and Chief of Staff Yitzhak Rabin said bluntly, "Last week's air strikes won't stop the shelling of our towns and settlements."
The pro-Labor Party Jerusalem Post editorialized. "The inherent logic of the present military strategy must lead to either an acceptance of the famous suggestion to 'bomb' em to the Stone Age,' made by a certain US general . . . or to the physical occupation of the entire base area of terrorism. The first option is unthinkable and the second would seem to be unrealistic."
Mr. Rabin urged a return to "selective" Israeli operations against the PLO to prevent shelling and infiltration into Israel. Ultimately, he added, the solution to "the problem of the terrorist organizations" could not be military. "It is political," he said.