The official Israeli line is that, with a cease-fire still holding across the Lebanese border, the Palestine Liberation Organization deliberately provoked the latest outbreak of violence in the occupied West Bank territory by way of showing its muscle somewhere. Arab diplomats contend that the Israelis started it--for the same reason.

Other analysts tie the Israeli crackdown to this month's final Israeli withdrawal from the Sinai, and the uprooting of the Israeli settlement at Yamit under the peace treaty with Egypt. They see it as Prime Minister Menachem Begin's way of reassuring traumatized Israelis that the West Bank and its dozens of Jewish settlements will never go the same way as the Sinai territory.

It's a bootless argument. Whatever dictated the timing, the most authoritative explanation for the sacking of three Arab mayors with PLO connections and the heavy reinforcement of Israeli occupation forces has been readily available since last May in an article in Commentary magazine. Its author: Menahem Milson, then a professor of Arabic literature at Hebrew University in Jerusalem and now the "civil administrator" of the West Bank.

Milson, a disarmingly congenial fellow, was handpicked for his current job by Israeli Defense Minister Ariel Sharon who in turn is the strongman in the Begin government on matters having to do with occupied territories. So Milson's treatise on "How to Make Peace with the Palestinians" can be viewed as something like holy writ on Israeli policy on the issue.

At this critical juncture, it cries out for careful reading, the more so since Milsonism is directly at odds with everything we know about the Reagan administration's plans for advancing the Camp David peace process.

Soon after the return of the Sinai, for example, the administration wants to put a full-court press on the Camp David talks on "autonomy" for the West Bank and Gaza, according to reliable authorities. This means trying to bring representatives of the Palestinians into the discussion--perhaps even the PLO itself, if it could first be prevailed upon to recognize Israel's right to exist.

But Milson, true to his prescriptions almost a year ago, has been playing an entirely different game, based on categorically different premises, since he took office last November. His first premise is that the PLO is inplacably hostile.

His second is that, by "physical terror," bribery and other nefarious means, the PLO corrupted the election process in the 1976 municipal voting, with the result that most of the mayors who came to power were unacceptably pro-PLO.

A third premise is that there are "moderate" Palestinians in large numbers ready to step forward if they can be freed of PLO intimidation. To this end, Israeli security forces have been busy jailing the most vigorous PLO sympathizers, placing others under town arrest, practicing their own brand of intimidation. Meanwhile, Milson practices a form of bribery by setting up a network of "village leagues," arming their members, and endowing them with authority to hand out building permits and other "patronage."

It is Milson's simple purpose to eliminate every possible vestige of PLO influence on the West Bank. The removal of the three mayors is no more than a predictable expression of that purpose, and almost certainly not the end of Milson's municipal purges. With his own "moderates" ultimately in key Palestinian leadership roles, Milson would be pleased to proceed with "autonomy." That Egypt's President Hosni Mubarak would not be is certain.

And what of the third party to Camp David, the United States? Milson has a seductive answer. In Commentary, he plays nicely to the Reagan administration's hopes for a "pro-Western strategic alliance in the Middle East." It can only be achieved, he argues, by winning over Jordan and Saudi Arabia (at a minimum) to the Camp David formula.

This, in turn, can only be done by "legitimation," Milson-style, of the Palestinian representation on the West Bank--which means "freeing the population of the territories from the grip of the PLO." For this, Milson insists upon "the support and cooperation of the United States."

How? "The way for the United States to help," wrote Milson, who is nothing if not bold, "is not to demand further concessions from Israel in order to satisfy the PLO." How the United States could accept the role of co-conspirator in this plot while remaining in the good graces of even the most moderate Arabs, Milson did not feel it was necessary to explain.

But that clearly is the Begin government's plot. Keeping the United States from getting caught up in it will require a lot more than the expressions of "regret" and appeals for "restraint" that have so far constituted the administration's response to violence on the West Bank.