BRUSSELS — Few Jewish couples define their marriage as “mixed” just because bride and groom were born and raised 30 miles apart in the same country.

But Linda and Bernard Levy live in Belgium, a country whose long experiment in fusing two distinct cultures recently has been showing signs of breakdown. With the Dutch-speaking Flemish half of the country increasingly at odds with the French-speaking part, Belgium’s corresponding Jewish communities are finding themselves at loggerheads as well.

Linda was born in Antwerp, the capital of Flanders in the self-governing Flemish region. She rarely uses Flemish (similar to Dutch), the language of her youth, since she married Bernard, a Francophone from Brussels. They live just outside Brussels with their three children.

“Language is actually a non-issue in mixed marriages like ours,” she said. “Flemish Jews are usually bilingual.”

But a recent rupture in relations between Belgium’s Flemish and French-speaking Jewish communities, each with approximately 20,000 members, has exposed some profound ideological differences between the two communities, particularly on Israel.

The trigger was Belgium’s decision in March to join Austria as the only two EU countries to vote in favor of a U.N.-led investigation of West Bank settlements.

Belgium’s Flemish and French-speaking Jewish communities long have maintained a modus vivendi for cooperation under which they always approached federal authorities together. But on the vote on the U.N. probe, the two communities broke with each other.

Flemish Jews, represented by the Forum of Jewish Organizations, or  FJO, met with Belgium’s justice minister and released a statement saying that “the Jewish community was shocked and appalled” by the vote.

By contrast, French-speaking Jews, represented by the Umbrella Organization of Jewish Institutions of Belgium — known by the French initials CCOJB — did not condemn Belgium’s vote. Instead, CCOJB’s president met a Belgian Foreign Ministry official who concluded that Belgo-Israeli relations were “warm and frank.”

The ministry “regrets certain disagreements are being used to import the conflict to Belgium,” CCOJB informed its members in a statement.

“The meeting at the foreign ministry would’ve gone differently had we been invited,” Eli Ringer, honorary chairman of the Antwerp-based FJO, told JTA. He noted that CCOJB, the organization representing Francophones, recently added to its board a member of JCall, a left-leaning Jewish group that describes itself as pro-Israel but also is critical of the Israeli government. JCall was modeled after J Street in the United States.

“I hope we can once more speak with one voice on the federal level,” Ringer said.

It was hardly the first dispute between the two Jewish communities. In December, Ringer criticized CCOJB for hosting as a guest of honor at a gala a Belgian politician who had equated Israel and Nazism. He called the move “unwise.”

Joel Rubinfeld, the previous president of CCOJB, says the two organizations have reached a point of an “open row.” Relations between the groups “have never been worse,” he said. His CCJOB successor, Maurice Sosnowski, declined to be interviewed for this article.

The Jews of Antwerp and Brussels long have been different. Jews from Antwerp tend to be more religious, tight-knit and hawkish on Israel, while their Brussels coreligionists are more liberal, according to laymen and leaders from both communities. Antwerp has 13 Jewish schools compared to three in Brussels.

Linda Levy’s father, a diamond dealer, is one of approximately 18,000 Jews living in Flanders. Most Flemish Jews in Antwerp are Orthodox and speak Flemish or Yiddish at home as well as French and Hebrew.

“I was raised in a largely secular home, but our family in Brussels thinks I’m some kind of religious authority because I’m from Antwerp and I light Shabbat candles,” Levy said.

Her husband, Bernard, hails from the Brussels Jewish community of about 20,000. Most of its members are concentrated in and around the French-speaking federal capital, where they lead secular lives.

The split between the Jewish communities of Belgium mirrors what in recent years has become a national woe: the widening gulf separating Flemish and French-speaking Belgians.

One of the first big splits hit the Belgian Socialist Party in 1978, two years before the creation of the Flemish Region and the onset of Belgian federalism, when the party split in two. There not only are two socialist parties now representing Francophones on the one hand and the Flemish on the other, but two Christian Democratic parties, two liberal parties and even two green parties. The secessionist New Flemish Alliance wants the Flemish part of the country to pull out of Belgium altogether.

The very creation of a separate institution representing only Flemish Jews was itself a part of the same process. Founded 50 years ago, the CCOJB umbrella group used to represent — nominally, at least — Jews from both Flanders and Wallonia, the French-speaking region of the country. But in 1993 the Flemish community splintered off and formed FJO, reflecting the sentiment that Jews from Antwerp were not really represented in the main community umbrella group.

Michael Freilich, editor in chief of Belgium’s leading Jewish publication, Joods Actueel, says the two communities inhabit two distinct political universes.

Due to the political system, “in Flanders you can only vote for Flemish parties and in Wallonia only for French-speaking parties, even though parties from both regions sit in government,” Freilich said. “This means politicians who matter to Wallonians don’t matter to Flemish and vice versa. It’s very difficult to lobby together when you inhabit two different, parallel political realities.”

Belgium’s political crisis resulted last year in a new world record: Belgium went for 541 days without an elected government because Flemish and Wallonian representatives could not reach a compromise. That was one of several crises since 2007 that has caused many in Belgium and elsewhere to doubt Belgium’s sustainability as a unified state.

Then there are intercultural gripes.

“The problem is that there are a few people in Brussels who are still used to thinking of French speakers as the elite and of Flemish speakers as provincial,” Ringer said.

The chairwoman of FJO, Kouky Frohmann-Gartner, put it more bluntly in an interview for Joods Actueel in October: “Those in Brussels think they’re better,” she said.

Yet Ringer says he is optimistic about the future of relations, at least among Belgium’s Jews.

“Every time the Brussels community gets a new president, they decide they need to represent the whole of Belgium. Then they get over it,” he told JTA. “We’re a small community that needs to work together to overcome similar challenges.”