A SEEMINGLY arcane religious dispute has evoked an unprecedentedly fierce reaction against Israel among American Jews and may affect the shape of the next Israeli government. The storm created in the United States by the so-called ``Who's a Jew?'' proposal, which would negate non-Orthodox conversions to Judaism among immigrants to Israel, has stunned Israeli political figures. ``This could create the greatest division we've ever seen in the Jewish world,'' warns Mendel Kaplan, chairman of the Jewish Agency, which serves as a liaison between Israel and the Jewish diaspora.
The proposal has brought threats from American Jews affiliated with the Conservative and Reform branches of Judaism that they would cut back on their financial and political support for Israel. Several delegations of American Jewish leaders have arrived in Jerusalem in recent weeks to emphasize that these threats are not mere rhetoric.
Although the proposed legislation would directly affect only a tiny number of people - non-Orthodox converts seeking to immigrate to Israel - Conservative and Reform Jews, who constitute 75 percent of America's 5.5 million Jews, see it as a declaration by the Jewish state that they are in effect second-class Jews.
``When I read about this in the papers, I felt betrayed, shocked, and furious,'' says Hubert Brandt, a New York lawyer and Conservative Jew whose daughter-in-law converted to Judaism from Roman Catholicism. ``This meant that my grandchildren, according to Israeli law, were not Jews. How dare they say that, when Hitler would have put them in ovens as Jews?''
It is estimated that more than 200,000 people in the US have been converted to Judaism in the last 20 years, most of them by Conservative and Reform rabbis.
The legislation would amend the Law of Return, which opens Israel's gates to any Jew who wishes to immigrate. Government officials ruled in the 1950s that any would-be immigrant who declared himself in good faith to be a Jew would be so accepted. This aroused the wrath of the Jewish religious establishment in Israel - exclusively Orthodox. Jewish law stipulates that a Jew is anyone who is born of a Jewish mother or who converts to Judaism by specific rituals that include circumcision, ritual immersion, and a declaration of acceptance of religious commandments. The Orthodox establishment asserts that Conservative, and particularly Reform, rabbis do not follow these strict requirements.
For about 30 years, Israel's small religious parties have attempted to insert a phrase into the Law of Return stipulating that it applies only to people who are Jews ``according to Jewish law.''
The Nov. 1 election gave the four religious parties unprecedented clout. They won 18 seats in the 120-seat Knesset, which meant that Likud leader Yitzhak Shamir could not form a government without them, since he had declared his intention not to form a new coalition with the Labor Party. In tough coalition negotiations, the religious parties extracted a pledge from Mr. Shamir that he would enforce party discipline to push the ``Who's a Jew?'' amendment through the Knesset within four months. Swallowing hard, Labor Party leaders had earlier indicated a readiness to support the amendment, which they had always denounced as divisive, if the religious parties supported a Labor government headed by Shimon Peres.
For both major parties, the amendment was an unpleasantness, but minor compared with the great issues concerning peace and territories which they expect to confront during the next four years. After all, they rationalized, the amendment would affect only a dozen or so Conservative and Reform converts who attempt to immigrate each year, and these could be accommodated by going through an Orthodox conversion as well.
American Jews, however, quickly let it be known that they did not regard the amendment as a minor nuisance but as a massive insult that directly challenged their identity as Jews. This reaction came not only from the numerous Jewish leaders who were married to converts or whose children were, but also from the mass of Conservative and Reform Jews who indicated they felt themselves being disenfranchised by Israel's Orthodox rabbis, who refused to grant equal status to their form of Judaism.
What has come to be termed in Israel ``the American revolution'' erupted in New Orleans in late November at the General Assembly of the Council of Jewish Federations, the principal Jewish fund-raising organization in the US. In front of 3,000 delegates, speaker after speaker rose to express anguish over the proposed amendment. Many ``big givers'' said they would withhold contributions to Israel. There were even reports that some leaders had called on the American government to cut back on the $3 billion it provides Israel annually in military and civilian aid.
``Only at the assembly did we recognize the intensity of the emotion on this issue,'' declared Shoshana Cardin, a former president of the council, who flew to Israel from New Orleans to warn the leaders of both major parties of the passions involved. Even a delegation of American Orthodox rabbis arrived to urge that the amendment be shelved because of its divisive impact.
In an ironic twist, the powerful American Jewish lobby, which normally attempts to influence the American government on Israel's behalf, called on the Reagan administration to intercede with Israel on behalf of American Jews. US officials did indeed express concern on the issue to Israeli representatives. Israeli diplomats in the US sent hurried warning signals to Jerusalem.
The strong reaction has startled Israeli leaders. There are clear signs that Likud politicians are attempting to find a way out. Citing the crucial importance to Israel of American Jewry, they have attempted to persuade the religious parties to shelve their demand. Shamir also dropped his initial objection to Labor participation in his government. If Labor joined, it would eliminate his dependence on the religious parties. He has steadily increased the price he is willing to pay Labor in the form of ministries, and perhaps even on the political direction of the new government.
The uprising of American Jews has shown Israel that the fundamental question of who is a Jew is not for Jerusalem alone to decide.