In 132 A.D., an arrogant young warrior assumed the Messianic name of Bar Kokhba ("son of the star") and organized what proved to be the fateful climax in Jewish uprisings against Roman rule. The suppressed inhabitants of Judea had persevered through tragedies like the Great Revolt 60 years earlier, in which the Second Temple was destroyed, and the self-martyrdom of 900 men, women and children at Masada. But Bar Kokhba's insurgency unleashed the decisive Roman assault that drove the Jews into the Diaspora. It took them nearly 2,000 years to regain their homeland.

For Prime Minister Menachem Begin and many other Israelis, Bar Kokhba represents an inspirational hero who chose honor over subjugation in his doomed struggle to win freedom for his fellow Jews. Israeli kindergarten pupils are taught to sing the praises of "a man young and tall with eyes that shone; he was brave and called for liberty."

But in the eyes of Yehoshafat Harkabi, professor of international relations and Middle Eastern studies at Jerusalem's Hebrew University, Bar Kokhba's exploits deserve censure rather than reverence, for he behaved like a naive, vainglorious romantic whose catastrophic campaign almost caused the extinction of the Jewish people.

Harkabi's bold challenge to accepted myth has caused an uproar this year in Israeli intellectual circles. What started as a modest pamphlet has snowballed into a controversial best seller titled "The Bar Kokhba Syndrome: Risk and Realism in International Politics," to be published in English this month by Rossel Books.

Harkabi's work is a painstaking study of the calamitous era of Jewish rebellion. Despite its esoteric nature, the book has gained widespread notoriety for the conclusion that Bar Kokhba's intransigent zealotry finds its current incarnation in Begin and his aggressive brand of Zionism.

In Israeli universities, synagogues and coffee shops, Harkabi's notions have aroused stormy debates over the provocative parallel drawn between Bar Kokhba and Begin--two strong-willed leaders whose ideological obsessions, the author claims, hinder pragmatic accommodations with enemies and court jeopardy for the Jewish state.

"You cannot admire bravery without looking at results, and in Bar Kokhba's case they were destructive to the Jewish people," says Harkabi. "Similarly, those who approve of Begin's defiant actions must bear in mind the possible long-term consequences...

"Begin in power has meant a primitivization of political thought in Israel. He feels that for 2,000 years, the Jewish people had no political experience and thus cannot sensibly weigh arguments. They must be told what to believe."

The balding, 61-year-old professor asserts that a "more discriminatory, realist school of thought" flourished under David Ben-Gurion and prevailed until the Six-Day War in 1967.

"That's when an overwhelming victory persuaded Israelis that they could get everything they wanted," he explains. "It fed an appetite for aggression and made people think that if you believe, if you have a strong will, you can do anything."

This transformation, Harkabi contends, reached its apotheosis with Begin's reelection last year. "He suddenly appeared as a wizard, hailed by his supporters as the new 'King of Israel,' claiming he got us peace as well as control of Judea and Samaria the West Bank ."

Harkabi's stature within Israel as a respected expert in three fields lends authority to his ideas. After serving as a company commander in the Haganah infantry during Israel's 1948 war of independence, he rose within the army to become director of Israeli military intelligence in 1955.

Despite a brilliant reputation as a spymaster/strategist, Harkabi felt compelled to resign in 1959 after one of his officers ordered a general mobilization of the country when, in fact, no threat had materialized.

Following this "mishap," as he calls it, Harkabi spent a year studying public administration at Harvard and then returned to Tel Aviv to serve as deputy director general of the prime minister's office.

In 1968, Harkabi embarked on a distinguished teaching and writing career in international affairs at Hebrew University and enhanced his position as one of his country's foremost Arabists.

Harkabi says that Israel should pursue policies that are "more lenient and magnanimous in spirit" and see if the Arabs will reciprocate.

Until the invasion of Lebanon, Harkabi's main conflict with Begin centered on contradictory perceptions of Israeli interests in the West Bank and Gaza.

Begin's ideological commitment to Greater Israel, extending to the banks of the Jordan River and perhaps even beyond, contains the seeds of destruction for the Jewish state, according to Harkabi.

"We simply cannot keep such an enclave [the West Bank]," insists Harkabi. "If we annex the land, Israel will eventually lose its Jewish identity by having to absorb 1 million more Arabs.

"If we occupy the land indefinitely by military force, this would turn the area into another kind of Belfast with endless quarrels between Arab and Jew."

The only possible solution, Harkabi believes, is a negotiated withdrawal, allowing for Palestinian self-determination and adequate safeguards for Israeli security. He also thinks that even if West Bank Palestinians initially opted for statehood, they would eventually form a federation with Jordan because of "demographic and geographic imperatives."

"Many West Bank and Jordanian Palestinians are part of the same families and do not wish to remain divided," Harkabi says. "In addition, the West Bank is landlocked and would require an outlet to the sea through Jordan."

In recent weeks, Harkabi has been busily revising his concluding chapter to incorporate what he believes are the tragic lessons of Israel's invasion of Lebanon.

"Let's first look at the gains," Harkabi says. "The PLO military force has been defeated, there is no longer the threat of long-range PLO weaponry threatening our northern towns, and maybe there will be a more stable government in Lebanon.

"Now let's look at the losses. Israel has suffered an enormous decline in its moral stature. The Palestinian problem is again in the world's eye, more prominent and pressing than ever. And we may have problems with the Lebanese government to establish a secure military zone along our northern border.

"In my view, there is no question that the gains will tarnish over time and the losses bequeathed by the war will become more troublesome."

Harkabi remains optimistic about prospects for "a new convergence of reality and reasoning" because, if anything, the Lebanon invasion has "proved that Israel's democratic spirit has been preserved through the courageous criticism of government actions by soldiers and the Israeli press."

His own criticism of the Begin government has caused him some personal anguish, but he believes his work will be vindicated if it promotes a helpful dialogue on the future course of his country.

"I may be a lone wolf, but I don't feel solitary at all," he says with a smile. "History is on my side."