Jerusalem — Despite mounting criticism at home of the conduct of the Lebanese war, its principal architect - Defense Minister Ariel Sharon - appears likely to emerge with laurels if he succeeds in pushing the Palestine Liberation Organization out of Beirut without excessive Israeli losses.
Public opinion in the past two weeks has teetered in Israel between regarding the war as a debacle and as a brilliant military and political achievement.
The initially announced war objective, pushing the Palestine Liberation Organization out of artillery range of Israeli settlements, had almost universal aproval in Israel. But as the Israeli Army spread far beyond the original 25 -mile line and casualties began to mount against the Syrians and the PLO, many began to question the direction and cost of the war. In addition, the view of battered Lebanese towns raised moral questions in Israel and created dismay at Israel's world image.
Critics accused Mr. Sharon of deliberately misleading the Israeli public and government by setting the country's war machine into motion in pursuit of his own grandiose political objectives under the pretext of a limited war objective. Mr. Sharon vigorously denied this, saying that the initially announced objective had been sincere but that it would have been wasteful not to capitalize on Israel's initial success to pursue other goals as well; principally ousting Syria and the PLO from Lebanon and the creation of a strong central government in Beirut that could make peace with Israel.
Much of the criticism stems from the fact that this is the first war Israelis perceive to have been waged not because of imminent threat but because of political calculations. The changing war objectives and ''fog of battle'' deliberately imposed by the government - presumably to befuddle the enemy about Israel's intentions - has created a sense of mistrust in some sectors of the population. For the first time ever in any of Israel's wars, there is some criticism coming even from soldiers on the battlefront about the merits of the war.
There have also been public demonstrations in Israel by the Peace Now movement and other liberal groups whose mistrust of Mr. Sharon is profound.
''There are men and officers who no longer understand the war's goals,'' wrote a Jerusalem Post military correspondent this week after a visit to the battlefront. ''They can understand the technical strategic advantage of capturing Bhamdun (a village captured from the Syrians last week) but they cannot fully understand why this should have been worth so many lives and wounded.''
Despite such criticism, Israel appears on the verge of a significant strategic victory. The virtual destruction of the PLO in Lebanon may not prevent terror attacks against Israeli targets - it may, indeed, increase them - but it relieves the tier of Israeli settlements along Israel's northern border from the fear of sudden bombardment. That threat has hung over them since last year's artillery skirmishing with the PLO across the border.
More significant is the possibility of peaceful relations with Lebanon. Although Lebanon's internal problems and its relations with the Arab world may make a formal peace treaty difficult to achieve, Israelis are enthusiastic about the possibility of relations that would permit commerce and tourism.
Defense Minister Sharon also apparently hopes that the blow struck at the PLO will make Palestinians on the West Bank and Gaza Strip more willing to negotiate with Israel on autonomy.
If Mr. Sharon manages to achieve these goals, most of the criticism may give way to grudging praise for his audacity and imagination.
Such chords can already be heard among circles on the political left. The chairman of the Jerusalem branch of the left wing Mapam Party, Col. Hillel Ashkenazi, called on his party this week to halt its attacks on Mr. Sharon's policy.