Defense Minister Ariel Sharon, who launched Israel's invasion of Lebanon eight months ago, today was in danger of becoming the principal Israeli victim of the bitter aftermath of that war.

Sharon is still using his considerable talents to fight the least equivocal verdict handed down in a long career that has stirred harsh criticism of him from most Arabs and some Israelis, and adoration from many Israelis.

But the Israeli commission of inquiry yesterday did Sharon grave damage by pinpointing his ties to the Lebanese Forces, the Maronite Christian militia that massacred Palestinian civilians last September in Beirut's Sabra and Shatila camps, as a major factor in Israeli responsibility in the killings.

Ironically, Sharon is a relative newcomer to the de facto alliance between Israel and the Lebanese Forces that was forged before he was in government.

But it was Sharon, commander of the controversial Unit 101 that in the 1950s conducted punitive raids in which Arab civilians were also slaughtered, who took the fatal step of committing the Lebanese Forces in action. That was something that Labor Party prime minister Yitzhak Rabin and his defense minister, Shimon Peres, had carefully ruled out when they inaugurated the relationship with the Lebanese Forces in the mid-1970s as a means of harassing the Palestine Liberation Organization and the Syrian troops in Lebanon.

In fact, Sharon simply built on the long, painstaking work that the Israeli military and especially Mossad, Israel's equivalent of the CIA, had set in motion during the Lebanese civil war in 1975-76.

Especially active was a shadowy figure long known only as "Mandy." He has been identified as Yizhak Hoffi, who until halfway through the 1982 war was the head of Mossad.

Another key Israeli involved with the Lebanese Forces was David Kimche, now director general of the Foreign Ministry. For years Kimche was a senior Mossad agent and became a close confidant of the late Bashir Gemayel, the founder of the Lebanese Forces.

Long before Israel invaded Lebanon on June 6, Hoffi, Kimche and other key Israelis were frequent visitors to the Lebanese Forces' stronghold in Christian East Beirut, often dining out with the cream of Christian society.

The 1982 invasion, which Sharon masterminded and led, showed, however, that the Israelis and Lebanese Forces had sharp and open differences. Repeatedly during the summer Sharon openly insulted the Christian militia for failing to join in the fighting.

Once Bashir Gemayel, Lebanon's president-elect, lay crushed to death in the rubble of a party building in East Beirut on the afternoon of Sept. 14, Sharon had little trouble in enlisting the leaderless Lebanese Forces to enter Sabra and Shatila.

Split into at least three mutually suspicious clans--which had been held together only by Gemayel's charisma--the Lebanese Forces were easily taunted into action. According to what key Lebanese Forces officials have been saying privately in mitigation of their role in the massacre, the most openly pro-Israeli faction was told it must act to avenge its fallen leader.

The Israeli commission's report singled out one Lebanese Forces commander by name--intelligence chief Elie Hobeika, who along with other Maronite commanders had been named in news accounts shortly after the massacre as having taken part in the killings.

The degree of Israeli control over the Lebanese Forces has been highlighted by the commission report's citing of two comments by Lt. Gen. Rafael Eitan, the Israeli chief of staff. At one point Eitan said he and his overall commander in Lebanon, Maj. Gen. Amir Drori, had instructed the Lebanese Forces to "order a general mobilization." At another point in his testimony, Eitan explained his preference for using the militiamen rather than reguar Lebanese Army troops in the camps "because we could give them the Lebanese Forces orders whereas it was impossible to give the Lebanese Army orders."

Thus the commission report contradicted testimony that the Israelis had first asked the Lebanese Army to clear out Sabra and Shatila. Drori, the report noted, had in fact been so fearful of the militia's past record of excesses that, acting on his own, he tried unsuccessfully to get the Lebanese Army to intervene in the camps to head off the Lebanese Forces. The testimony noted that Drori had taken a senior Lebanese Army officer out to Beirut airport, where 1,500 Lebanese Forces then were gathering, and said that if the Army didn't do the job he knew men who would.

The commission suggests that Sharon and his commanders persuaded themselves that because the Lebanese Forces wore Israeli-style uniforms and used much Israeli-supplied materiel, including helmets and boots, that they were a disciplined force responsive to Israeli command. And Sharon apparently still believes that rough tactics can bring the Maronites around.

Just last month Sharon shocked many Lebanese Christians by leaking word of his tough meeting with Pierre Gemayel, founder of the Phalangist Party, which provides the lion's share of the Lebanese Forces troops.

Sharon told the elder Gemayel that if his son, President Amin Gemayel, didn't start cooperating, Israel would abandon the Maronites to the tender mercies of the Syrians, Palestinians and Druze, and that the Maronites would then have to rely solely on the uncertain backing of the United States.

Unless the Lebanese government did what it was told, Sharon said he would withdraw Israeli troops to a 30-mile-deep zone north of the border, thus all but assuring the partition of Lebanon among Israelis, Palestinians and Syrians.

Sharon's personal involvement in Maronite politics was then demonstrated when some of the Lebanese Forces' top commanders rushed to Sharon's farm in the Negev desert for reassurance. As they have done often in the past, the Israelis leaked word of their compromising mission.

Then last weekend, the Lebanese Forces charged that the Israeli Army had stood idly by as Druze troops kicked them out of the key mountain town of Alayh, inflicting heavy casualties.

Whether the pro-Israeli wing of the Lebanese Forces has finally got the message remains unclear. But even in East Beirut it has become popular to blame Sharon for everything, from the Lebanese Forces' heavy casualties in the Chouf Mountains fighting to the recent spate of incidents in which the French contingent of the multinational forces has suffered casualties and a series of showdowns has been provoked between American Marines and Israeli troops.