FOR DECADES, the contrast in character between Israel and the Moslem world was a given, at least to the West. Israel was modern, democratic, ruled by reason; the Moslems were medieval, autocratic, ruled by passion. When journalists a few years ago identified an anti-rational "Islamic resurgence," it was greeted with a certain "so-what-did-you-expect?" Then its counterpart came along, a "Judaic resurgence," which threatened to abort the prospects for peace in the Middle East. Observers are still trying to get it into perspective.

For American policymakers it seemed true to form, though surely exasperating, that in Iran a band of militants defies the world and makes national policy, that in Lebanon and Saudi Arabia and Syria hostile religious sects wage civil war, that in Pakistan and Libya favored cliques impose fusty legal codes. When Israelis start behaving that way, we take comfort in their being reasonable (like us), and our diplomacy proceeds as if good sense will soon prevail.

In fact, the Judaic resurgence much resembles its Moslem counterpart. To be sure, the Islamic movement has assumed different forms as it has spread from one country to another. But rather uniformly this resurgence, whether Jewish or Moslem, has been spearheaded by small factions of zealots who, disdaining to maneuver from within, seek to dominate the political system from without. This zealotry, furthermore, though pursued in God's name, is highly nationalistic. It is directed not to the attainment of new levels of spirituality but to political ends.

The resemblance, I think, is no coincidence. Though the Islamic wave is often explained as the product of a new self-confidence among Moslems, I would argue the contrary: that it is the bitter harvest of the 30 years of postcolonial freedom, which have produced social frustration, political turmoil and painful feelings of inadequacy. One should note tha the Judaic resurgence dates not to the buoyant victory of 1967 but to the Yom Kippur War of 1973 when Israel, though ultimately a winner, was shaken to its roots, both by Egypt's unexpected military prowess and by the recognition of its own complacency, squabbling, leadership failures and general flabbiness.

Gush Emunium, the organizational wedge of the Judaic resurgence, was founded after the Yom Kippur War. If there is a prototype among its members, it is a young man or woman whohas attended a university, has been trained in a profession, has upwardly mobile aspirations -- and feels insecure. I have met Americans of this description in some of the cults which have abounded in this country in recent years. I have also met Egyptians like them in the Moslem Brotherhood, which is the avant-grade of the Islamic wave that proposes to engulf President Sadat and the Middle East peace treaty.

Israel's Gush Emunium people, who share the Moslem Brotherhood's contempt for the peace treaty, are looking for roots, and for meaning, in Jewish identity. "The Bible says we Jews are a mountain people," a Gush Emunium settler on the West Bank told me. "This is where we belong, not down by the sea in Tel Aviv." At another settlement, a young mother whose husband worked as a teacher in Jerusalem conceded to me that she did not enjoy the bleak, often frightening landscape of the West Bank, but she said that being a pioneer on these once-Jewish lands gave her a sence of purpose that she had never experienced before.

Other characteristics which the Judaic resurgence holds in common with its Islamic counterpart are an extreme intolerance of disagreement and a penchant for violence. In societies accustomed to the shedding of blood in political strife, the two tend to go hand in hand.

In Egypt the Brotherhood, which regularly attacks left-wing political meetings and "un-Islamic" rock concerts, has recently added the burning of Christian churches to its program. In Israel, Jewish fanatics on the West Bank have shot at Arab demonstrators, have beaten up Arabs at random and have even defaced Arab places of worship. In both countries, these movements are so intimidating that they have perpetrated their crimes without the state's exacting serious penalties for them.

In Israel, furthermore, the government openly sympathizes with many of the goals of the Mudaic resurgence, which helped elect it, but Gush Emunium has nonetheless forced on it unwanted policies, jeopardizing the peace. Last year a band of 300 settlers girdled themselves in barbed wire, armed themselves with pipes and stones and, vowing their readiness to die, won a series of concessions for surrendering a patch of farmland in the Sinai that had been promised to Egypt under the treaty. Gush Emunium warned, however, that its retreat from the Sinai would not be a precedent for the West Bank, where it would wage civil war rather than relinquish the land to the Arabs.

Since then, the government has backed down several times before the settlers' threat of collective violence. At Elon Moreh, most notably, the Israeli Supreme Court ordered the evacuation of land illegally seized from its Arab owners, but Gush Emunium denied the court's jurisdiction, on the ground that a mandate drawn from the Bible takes precedence. Declining resettlement funds, Gush Emunium refused to leave, and the government, inviting the world's contempt, meekly submitted.

"Israel is secure with God," Gush Emunium replies when it is accused of risking Israel's future by making a fetish of the land. Long committed to secular doctrines, Israel for the first time in its history is experiencing a powerful political movement that claims to draw its inspiration from the Jewish faith. It finds its allies in Israel's traditional religious parties, marginal forces which have worked assiduously for decades to push the state toward theocracy, and with the help of Gush Emunim have recently won important legislative victories. Though Gush Emunim is itself short on spirituality, it shares with the parties of religious orthodoxy the certainty of following God's will, which inevitably imparts to the entire alliance a profound sense of its own self-righteousness.

The mirror image of this self-righteousness is xenophobia, which has made much of the country -- including the ruling circles -- impervious to criticism from abroad. In contrast to the Arab world, Israel remains an open society, and political debate continues to rage tumultuously. Still, as the Judaic resurgence has swelled, what Jefferson called a decent respect for the opinions of mankind has declined. Always on the alert for anti-Semitism, Israelis now see it increasingly -- sometimes accurately, sometimes not -- in rising international criticism. Each new U.N. resolution is taken as further proof that the universe is ganging up. Each expression of disapproval seems to elicit retaliation, often in the seizure of Arab land, as if Israel needs the criticism which inevitably follows provocation to show how deeply it is unloved. In this disapproval much of Israel finds perverse comfort, and a rationale for closing ranks against the hostile forces of the non-Jewish world.

It is common these days in Israel to hear talk of a pervasive "Masada complex." The name comes from the archeological ruin on the shore of the Dead Sea, where 1900 years ago a thousand religious zealots committed suicide rather than submit to foreign rule. The term is normally used to mean a fight-to-the-death courage as the enemy closes in, but it also contains a kinship with the Ayatollah Khomeini's boast that he and his followers welcome Islamic martyrdom. The Israeli fascination with the "Masada complex" raises a serious question of whether today's Israel, driven by a Judaic resurgence, has set itself upon a Masada-like course.