The ‘Who is a Jew’ dispute has become even more contentious since Israel’s chief rabbinate has begun questioning conversions made under Orthodox auspices.

Nearly two years ago, a Danish-born Israeli woman named Yael and her husband appeared before the rabbinical court in Ashdod to end their marriage. Since the couple had agreed on an amicable divorce, they anticipated a pro forma procedure.

Yael could hardly have expected that the court would declare that her Orthodox conversion to Judaism was null and void. Nor could she have known that her case would set off the latest round in the long-running Israeli dispute over who is a Jew. By no choice of her own, she is now at the center of overlapping debates on the meaning of conversion in Judaism, and over the connection between religion and state in Israel.

Yael grew up in a prot­estant home. In the late 1980s, while traveling in the Far East, she met a young Israeli man. She came to Israel to visit him and stayed. When they decided to marry, she chose to convert.

“Every­one told me it was very, very difficult to get along here without being Jewish, and difficult for the children. And I also liked it,” she recalls, referring to becoming Jewish. “Dur­ing the conversion…I un­der­stood ev­ery­t­hing hap­pen­i­ng around me,” in Israeli life and the rh­ythm of the Jewish year.

She was accepted into Ju­daism by a special rabbinic court devoted to conversions, under the auspices of the state’s chief rabbinate. The head of the court was Haim Druckman, a prominent religious Zionist rabbi and yeshiva dean. The wave of aliya from the Former Soviet Union had begun, and many of the new immigrants were not Jew­­ish under Orthodox law. Druck­man sought to give them the chance to convert.

Speaking to me, Yael asked to use the Hebrew name she took when she converted, al­though she normally goes by her Danish name. She wants to protect her children’s privacy. She also prefers not to talk about her level of religious ob­servance, which has become a matter of le­gal contention. But a recent court petition on her behalf notes that she fasts on Yom Kippur, builds a sukka at Sukkot and does not eat hametz during Passover. On the Israeli spectrum, that puts her on the traditional-lean­ing side.

Eventually, her marriage unraveled. At the divorce proceeding, the judge—Rabbi Av­raham Atya—discovered she was a convert. He started posing questions. Did she go to the mikve? he asked her. No, Yael said. Did she keep Shabbat? Partly, she said. She did not realize the significance of the questions.

But instead of getting a divorce certificate within a few days, she waited two months—and then received a judgment from Atya declaring her conversion invalid. She was not Jewish, he wrote, so she had never been married. Her children weren’t Jewish either.

“It was a big, big shock,” she says. “I feel I’m Jewish.” Her children have been raised as Jews; her son recently celebrated his bar mitzva. “The whole foundation of our family life—I felt like it’s breaking apart.”

Immediately, she asked for help from the Center for Women’s Justice, a nonprofit group that seeks solutions to the problems that women face because marriage and di­vorce are governed by the rabbinate in Israel. CWJ filed a petition with the High Rabbinic Court, which hears ap­peals of rulings from regional religious courts on family, inheritance and other issues.

The appeals court’s decision last spring was an earthquake. For practical purposes, the court up­held Atya’s position on the conversion. It also cast doubt on thousands of conversions performed by Druck­man, who by now headed the Conversion Authority, a government agency set up in 2004. And it told the chief rabbinate’s marriage registrars to treat all conversions, “from any rabbinic court in the world,” with suspicion.

Even “an outward appearance…far from the appearance of a religiously observant person” was reason to doubt that someone had converted properly, it stated. The court did not specify exactly how long a woman’s skirt or sleeves must be today to prove that her conversion years ago was valid, but it had placed its considerable religious and legal authority behind a radical innovation in halakha, religious law.

As Bar-Ilan University scholars Avi Sagi and Zvi Zohar explain in their recent book on becoming Jewish, Transforming Identity: The Ritual Transformation From Gentile to Jew–Structure and Meaning(Continuum International Publishing Group), rabbis have agreed through history that conversion “is as irrevocable as birth to a Jewish mother.” Once Jewish, always Jewish.

In contrast, the court’s ruling makes conversion conditional. If someone’s current behavior does not fit a standard of observance (and it is not clear what standard), it proves she or he was not sincere when accepting Juda­ism, and the conversion can be annulled. The idea of conditional conversion has been promoted since the 1980s by an Is­ra­eli rabbi, Gedalya Axelrod, and has gained support in ultra-Or­thodox circles. Now it has the backing of the High Rab­binic Court.

Besides that, the ruling highlighted divisions within Ort­hodoxy, with some rabbis regarding others as unqualified to perform conversion. Once, the “Who is a Jew” fight was about Reform and Conservative conversions; now even an Orthodox conversion certified by the Israeli chief rabbinate may not satisfy an Israeli rabbinic court, or the rabbinate’s own registrars.

To understand the crisis, remember that being Jewish has two legal implications in Israel. Under the Law of Return, every Jew has the right to im­migrate to Israel. That legislation defines Israel as a refuge for all Jews, but it didn’t originally say what “Jew” meant. In 1970, the Knesset belatedly defined a Jew as someone who was “born of a Jewish mother or converted to Ju­daism.” At the same time, it gave anyone with a Jewish father or grandfather the right to immigrate—a clause meant to cover those who may have faced ethnic persecution as Jews abroad.

Since then, Israel’s secular Supreme Court has ruled that a Reform or Conservative conversion abroad makes one eligible for aliya. (It has not yet ruled on non-Or­tho­dox conversions in Israel.) In turn, religious parties pushed to amend the law to recognize Orthodox conversions only.

The battle spilled over into the diaspora. “American Jewry would go into crisis mode,” its leaders insisting that Israel couldn’t delegitimize the non-Orthodox denominations, says Jonathan D. Sarna, the author of American Judaism: A History (Yale University Press). Arguably, diaspora pressure is what foiled the change.

In parallel, a legal system inherited from Ottoman and British rule assigns marriage and divorce to religious au­thorities. For Jews, that means the state’s chief rabbinate and rabbinic courts. Those bodies recognize only Or­tho­dox conversions.

Over the years, as ultra-Orthodox parties gained electoral strength, they horse-traded to put their appointees in the rabbinate and rabbinic courts. Those rabbis tend to be skeptical of the Jewishness of people who do not share their lifestyle. One result, as I documented in The New York Times Magazine (“How to Prove You’re a Jew,” March 2, 2008), is that immigrants born as Jews face difficulties proving they are Jewish in order to marry in Israel.

The rabbinate has also become less willing to trust Or­tho­dox conversions, except those performed by a select group of rabbis. Earlier this year, the Rabbinical Council of America- a group that represents modern Or­tho­doxy—ag­reed to create a network of conversion courts following standardized criteria for accepting converts. The move followed pressure from Israel’s Sefardic chief rabbi, Shlomo Amar.

When mass immigration from the FSU began, the gap between definitions of Jewishness became glaring. Many people who qualified under the Law of Return were not Jewish under religious law. Some identified ethnically as Jews. Some simply welcomed the chance to immigrate to a Western country. Either way, they have joined the ma­jor­­ity Jewish society in Israel. In ethnic terms, they are assimilating into Jewish culture. Official figures show 300,000 such people now live in Israel.

Druckman’s conversion court represented one re­sponse, favored by religious Zionists and some secular politicians: Provide people with the chance to convert, so that ethnic and religious identity line up. The rabbinate apparently provided its backing because of Druckman’s status. Sev­eral thousand people have converted under his auspices. But the Conversion Authority’s future is unclear. In June, Druckman was dismissed, officially because he had reached the age of 75. No replacement has been named.

The high rabbinic court’s decision has brought several issues to a head. In religious terms, it shows how deep the fissures are within Ortho­doxy. In the past, Reform and Conservative rabbis needed to warn prospective converts that they might not be accepted as Jews by everyone. Orthodox rabbis may now need to do the same. The RCA cannot really guarantee to converts accepted by its new courts that they will be accepted by the Israeli rabbinate. They could meet the same doubt as Druckman’s converts. In a divided Jewish world, no conversion promises universal acceptance.

The ruling also highlights a civil rights problem. Of­ficially, Yael is not married—and she has no way to remarry if she ever wants to, except to go abroad for a civil ceremony. Nor can her children marry. They are in the same boat as the 300,000 immigrants.

Susan Weiss—the founder and director of the CWJ and herself an ob­ser­vant Jew—has petitioned the Is­raeli Supreme Court to overturn the rabbinic court’s decision. But she also states, “We should have civil marriage. It’s going to have to happen.”

One reason that issue is so controversial, according to Weiss, is that it raises questions about what it means for Israel to be a Jewish state and about the connection of religious and ethnic Jewish identity. For many religious Jews, the rabbinate’s monopoly on mar­riage expresses the idea that Is­rael is a religious polity. In theory, it creates a single, shared standard for who is Jewish and prevents intermarriage in Israel.

But today, it is clear that Israel has inherited the same ambiguities of Jew­ish identity that exist in the diaspora. Indeed, that is a consequence of the Law of Return. Even if Israel chooses to tighten the rules for immigration, the fact will re­main: A large number of Israelis speak Hebrew, think of themselves as ethnic Jews, yet are not Jewish halakhically. Not many choose to convert—and converting does not bring a full resolution of identity.

The Supreme Court has yet to rule on Yael’s case. There is a strong chance that it will find that the rabbinic court acted improperly by raising the question of Yael’s Jewishness and will order the rabbinic judges to reconsider the case. Hopefully, that will restore her status as a Jew.

However, it will not resolve the wider issues of conversion and civil marriage and Jewish identity. In fact, if there is one thing all Jews agree about, it is that they all disagree about “Who is a Jew.”