THE New York jury that will shortly consider Gen. Ariel Sharon's $50 million libel suit against Time magazine may by its verdict determine whether the former defense minister ever becomes prime minister of Israel.
It is unlikely that this was foreseen by General Sharon when he initiated legal proceedings against Time, nor could others have foreseen in 1983 that Sharon would soon be back in the thick of Israeli politics.
Sharon's fortunes were then at a low ebb. The Kahan Commission had recommended his dismissal as defense minister after finding him guilty of ''blunders'' contributing to the Phalangist massacres at Sabra and Shatila by neither anticipating the possibility of Phalangist vengeance against residents of the Palestinian camps nor taking steps to prevent such massacres.
While rejecting the commission's findings, Sharon was forced to relinquish the Defense Ministry, remaining a minister without portfolio in then-Prime Minister Menachem Begin's government.
Sharon's reputation was further impaired as Israel's Lebanon invasion evolved into a frustrating open-ended occupation of south Lebanon at high cost and marginal strategic consequence. In retrospect, Sharon's inflated hopes for the operation - driving both the Syrians and the PLO out of the country, imposing a pro-Israel government on the warring Beirut factions, and indirectly smashing PLO political influence on the West Bank - appeared as impulsive as his having permitted the Phalangists to enter Sabra and Shatila.
Israeli analysts also rebuked Sharon for concealing his true Lebanon objectives even from the Begin Cabinet.
By mid-1983, Mr. Begin was finding leadership of the Israeli government more taxing than he could bear. His successor, Yitzhak Shamir, seemed an unlikely choice to maintain the Likud Party's hold on power, as Israel's economy worsened and Lebanon began eating up its reserve forces one and two at a time.
Thus Sharon's lawsuit appeared at the time an essentially private action by a man eager to salvage at least some of his honor against the Time contention that a secret Kahan Commission report appendix had found him discussing a need for vengeance with the Phalange over the murder of President Bashir Gemeyal.
But if Sharon then appeared the prodigal son of a party on the way out of power, the next 15 months would witness his stunning political rehabilitation.
For one thing, Begin's departure left a populist movement consisting mainly of North African Jews, young nationalists and territorial expansionists whose minions soon found a new hero in the bullish, flamboyant Sharon. Cries of ''Ariel, king of Israel'' quickly became a staple at Likud political rallies.
For another, Begin's decimation of the old Labor alliance, which had governed Israel during the first 29 years of statehood, was so complete that, despite Likud problems, Labor was denied a decisive victory in the July 1984 election and was forced into a post-election ''national-unity coalition'' with the Likud.
Sharon was quick to seize the opportunity, first running a strong if losing race against Mr. Shamir for leadership of the Likud and, with his Likud base again secure, wedging his way into membership on the pivotal 10-member ''inner Cabinet'' of the new government, this time as minister of industry and commerce.
Suddenly, Sharon's case against Time was no longer a private action but something approximating an act of state by a very public man. And his foes, both in government and the press, have been merciless in taking him to task for the conduct of his suit.
Many find it appalling that after an incident attributable in part to his own role in the affair, which resulted in the murder of hundreds of innocent men, women, and children, the primary object of Sharon's outrage appears to be Time's alleged insult to his own reputation.
Israel's press has also ridiculed his claim that he is suing to redeem Israel or even world Jewry from the ''blood libel'' of Time magazine, a term associated by many in Israel, a nation formed from the ashes of Hitler's Holocaust, with far more egregious acts of anti-Semitism.
More prosaically, many wonder why Israel's minister of industry and commerce finds it necessary to spend so much time in New York during a period of serious economic crisis in Israel and why the state has been required to advance money for his travel and hotel expenses.
Still others see the lawsuit refreshing worldwide recollections of Sabra and Shatila even before Israel has fully extricated itself from Lebanon.
And there has been the tricky business of the Israeli government's having to review court requests for witnesses and documentary evidence, denying several on national-security grounds, worrying about the suspicion of a cover-up among the millions of Americans following the proceedings in the news media.
All of which has led General Sharon's old chief of staff, Gen. Haim Bar Lev - now a Labor member of the ''inner Cabinet'' - to complain, ''Sharon has claimed that the state of Israel is on trial, but he did not bother to ask the country - or the government - whether it is interested in such a trial.''
Yet a jury verdict favorable to him could once again turn things around for this resourceful winner of many military campaigns.
A victory by Sharon would redeem a widely shared Israeli perception of unfair treatment by the Western press which many here feel applies far more stringent standards to Israeli conduct than that of neighboring Arab regimes or political movements.
Sharon has promised to repay the government for funds expended on his behalf, and if he wins, to use the proceeds to support vindication for other Jews who may have been maligned in the world's media. With a big enough verdict, Sharon could even pocket a few million dollars while still appearing something of a cross between Judas Maccabaeus and Robin Hood.
Israelis who love Sharon will, of course, continue to love him even if he loses his case against Time. Israelis who hate him will continue to do so even if he wins. But many Israelis harbor more complex feelings about Sharon, about Lebanon, and about the Western news media. And for them, the verdict of an impartial New York jury will be very important.