In 1987, approximately 1,800 Americans emigrated to Israel. Of them, only 22 were converts whose conversion was conducted by rabbis from the Conservative or Reform movements of Judaism.

But their status, or more properly the status of other converts who might follow them, has thrown the Israeli political process into turmoil. It has outraged the bulk of American Jewish leadership and sparked a debate on the role played by Diaspora Jewry - those Jews outside Israel - politically, religiously and financially, in the life of Israel.It is a debate with long-term consequences for both American Jews and the state of Israel, and its political process is belied by the minuscule numbers involved.

At the heart of the increasingly strident debate is the Israeli Law of Return, which guarantees Israeli citizenship to any Jew who emigrates to Israel.

But in recent years, ultra-Orthodox groups in Israel, formed into religion-based political parties, have been demanding changes in the Law of Return that would narrow its application to recognize as legitimate only those conversions conducted by Orthodox rabbis.

The last effort to change the law was in June 1988 when two bills were offered in the Israeli Knesset. Both failed by seven- to nine-vote margins.

Given the essential standoff between Israel's two major secular political blocs, the Likud and Labor parties, the Orthodox religious parties have assumed the power to make or break a government and have linked their consent to movement on their religious agenda.

That linkage, however, has outraged wide sections of American Jewry, both the religiously observant and the secular.

"While the numbers are minuscule, the larger principle of disenfranchisement of Conservative and Reform Jews is at stake," said Gunther Lawrence, a spokesman for the Synagogue Council of America, the umbrella group for the major rabbinic and congregational arms of the three major denominations of religiously affiliated Jews.

But he also said the dispute was "within the family" and that it would not undermine general support for Israel among American Jews. "I think an open, honest discussion within the family always strenghtens the family."

Although Orthodox Jews dominate the Israeli religious landscape, Conservative and Reform Jews far outnumber the Orthodox in the United States, with more than 3.3 million of the 4.5 million religiously observant Jews.

The three groups are distinguished by their approach to Jewish law and custom, with the Orthodox adhering to a strict intrepretation of Jewish halacha, or law; the Conservatives adopting a more moderate view that seeks to remain faithful to halachic tradition, while engaging in some modernization; and Reform Jews much more willing to reinterpret tradition in the light of the modern experience.

Equally important, U.S. Jews pour hundreds of millions of dollars annually into Israel and for other Jewish causes through a vast network of charitable and philanthropic organizations. And large portions of that money goes to support Orthodox institutions, both in Israel and in the United States.

The result is likely to be increasingly selective support of causes rather than any lessening of aid to Israel.

Conservative leaders made that clear last week, issuing a statement calling on adherents to "reassess their philanthropic support of institutions and movements in the Diaspora and Israel that do not support religious pluralism, democratic principles and reciprocal respect."

A particular target of the reassessment may be the Lubavitcher Jews, a sect of ultra-Orthodox Hasidic (or, "pious ones) Jews with Eastern European roots. The New York Orthodox group has been in the forefront of the decadelong demand that the Law of Return be amended, and some leaders believe the issue has as much to do with strained relations between the groups in the United States as it does with Israeli politics.

Conservative leaders said many of their members provide money for educational and other activities of the Lubavitch sect.

"We condemn the extreme Orthodox organizations and their leaders in North America who are dividing the Jewish people by inserting their religious-political agenda into the complex political life of the state of Israel," the 10 heads of Conservative groups in the United States and Canada said in their statement.