Jerusalem — Three men of public integrity have produced a dramatic, 108-page document that is already sending political tremors around the Middle East and as far as Washington.
The final report of Israel's Kahan Commission of Inquiry into the massacres in two west Beirut Palestinian refugee camps in September absolved Israel of any direct responsibility for the slaughter but charged the country's top political and military leaders with ''indirect reponsibility'' for the killings.
In so doing, basing itself more on moral than on legal grounds, the commission:
* Scores a stunning moral triumph for democratic processes in a region not noted for morality in war or politics, and in a country much criticized in recent months by international media and some American officials.
* Throws Israel's Likud coalition into turmoil by calling for the resignation of controversial Defense Minister Ariel Sharon - charged with ''personal responsibility'' for the events - and chastising Prime Minister Menachem Begin's conduct of government.
* Leaves the wider Mideast issues of Israeli-Lebanese peace negotiations and President Reagan's initiative for a broader Mideast peace hanging fire while Israel sorts out its domestic crisis.
The commission was established by the Israeli Cabinet on Sept. 28 after widespread public protest at Prime Minister Begin's initial resistance to a public investigation of the massacres.
It places direct responsibility for the killings squarely on the Phalangist Christian Lebanese militia, allied with Israel.
But, the commission said, those Israeli political and military officials who ordered the bitterly anti-Palestinian Phalangists into the camps to wipe out remaining PLO fighters ''should have foreseen - from the information at their disposal and from things which were common knowledge - that there was danger of a massacre.'' And if they did nothing to prevent it, then they are ''indirectly responsible for what ultimately occurred.''
The commission said that an ethical basis for such responsibility could be found in biblical Judaism and in the traditional attitudes of diaspora Jewish communities who believed that guilt for anti-Semitic outrages lay not only with the direct perpetrators but also with the government authorities who failed to prevent the attacks.
The commission noted briefly that indirect responsiblity for the killings did not lie with Israel alone, mentioning the Lebanese Army and the Lebanese government, and US representatives in Beirut who failed to persuade the Lebanese Army to take responsibility for public order. (Lebanon's chief military prosecutor, Asaad Germanos, head of Lebanon's own faltering investigation in the massacres, recently told the New York Times that he did not know who committed the massacre, how or when it was done, or even if it was done.)
The commission could have followed the precedent of a 1974 inquiry into Israel's unpreparedness for the 1973 October war, which made recommendations only against military leaders.
But the Kahan Commission boldly chose not to spare the political echelon. It accused Mr. Sharon of disregarding the danger of bloodshed and not ordering its prevention. It charged Mr. Begin with paying lax attention to the event in Beirut and Foreign Minister Yitzhak Shamir with not acting on a warning about the massacre, while not making specific recommendations against either.
The domestic Israeli political fallout from the report will be of intense interest to the United States. The Reagan administration harbors an ill-concealed hope that the Begin government might give way to a Labor government more amenable to territorial compromise on the Israeli-occupied West Bank - critical to the success of the Reagan peace proposal - and to a compromise on security arrangements facilitating Israeli troop withdrawal from Lebanon.
The report has created an acute political dilemma for Prime Minister Begin. While its recommendations are not binding, they carry intense weight. The commission recommends that Begin sack Defense Minister Sharon if the latter does not resign. Some Cabinet ministers have suggested Begin should offer the defense minister another Cabinet post. But Sharon's initial reaction has been not only to refuse to hand in his portfolio but to praise those military officers, from Chief of Staff Rafael Eitan down, who came in for severe criticism. (General Eitan's dismissal was not recommended by the commission only because he is due to retire shortly.)
Begin might find it awkward to fire Sharon, the architect of his policy in Lebanon, without dissolving his entire government. Israeli state radio reported Tuesday night that Begin had already made it clear that he would not ask for the resignation of Sharon.
The prime minister did hint last year that he would resign if the commission cast aspersions on him personally, and he is known to favor early elections, which he still believes he would win handily.
But to call new elections, Begin must seek a majority vote in parliament and some of his coalition partners, notably the National Religious Party (NRP), oppose early elections because they fear they would do badly. If Begin presses the NRP, it might leave his government and form a new governing coalition with Labor, thus causing a change of leadership without new elections.