JERUSALEM – As Israeli forces mobilized in the summer of 2005 to remove 8,000 settlers from the Gaza Strip, anger mounted among American Orthodox Jews.

Not only was Israeli Prime Minister Ariel Sharon’s government relinquishing territory some viewed as Jewish land by birthright, but many felt the withdrawal was a concession to terrorist intimidation that would invite further bloodshed.

But the Orthodox Union, the largest Orthodox umbrella group in the United States, remained silent, following a longstanding policy of not taking public positions opposed to the security policies of Israel’s government.

That policy was reversed recently when the Orthodox Union adopted a resolution at its biennial national convention in Jerusalem empowering its leaders to publicly oppose Israeli government positions if they deem it necessary.

At the end of a four-part resolution on Israel — which expressed, among other things, the union’s “historic obligation” to preserve the rights of Jews to live freely throughout the land of Israel and its skepticism about trading land for peace — the O.U. moved to allow itself to publicly oppose the government in “exceptional circumstances,” as determined by the organization’s board of directors or executive committee.

The resolution’s practical impact may be only to change the focus of debate from whether to dissent publicly to what qualifies as exceptional circumstances.

But its adoption, and the intensity with which delegates argued over seemingly minor distinctions in language and emphasis, reflects a larger generational shift within the union.

“This organization is becoming a lonely place for those who believe in old-fashioned modern Orthodoxy,” said David Luchins, a longtime O.U. board member who opposed the change. “The older generation was influenced by teachers who taught us not to get involved in Israeli issues. The grassroots is not satisfied anymore with that approach.”

Proponents of a more robust public posture counter that Orthodox Jews have a religious duty to make their voices heard on issues of consequence for the future of Israel and the Jewish people.

“If you’re going to be perceived as the organization that represents Orthodox Judaism in North America, you have an obligation,” said Aron Raskas, a Baltimore attorney who chaired the commission that drafted the resolution.

Raskas acknowledged that opposition is sometimes best expressed privately, but said there are moments that call for a more public position.

“Silence is often construed as tacit approval of the policy,” he said.

Diaspora Jewry’s role in Israeli decision-making long has been contentious, with many arguing that since Israelis alone bear the consequences of their government’s actions, American Jewish organizations have no right to influence them.

But Israel’s withdrawal from Gaza, with the spectacle of Jews removing other Jews from their homes, sparked a groundswell of protest in the Orthodox community that severely challenged that view. Raskas called it a “lightning-rod issue” for the Orthodox Union.

At the convention, debate over the union’s proper role in Israeli decisions essentially pitted the moralists against the pragmatists — those who believe American Jewry has an obligation to speak out against those who worry that the costs may outweigh the benefits.

Hillel Halkin, a noted author and translator who participated in a panel discussion on the subject, reminded the group that if it speaks out, other organizations will too. The cumulative effect will be a diminution of American Jewish influence on matters pertaining to Israel, he said.

Americans are just as divided on Israel-related issues as are Israelis, Halkin argued, and a split in the American Jewish community “could nullify its utility as an Israel lobby.”

During the question period that followed, it appeared Halkin’s urging had fallen on deaf ears. Virtually every questioner asserted not only a right but a moral imperative to oppose policies they believe put Jewish lives at risk, with many drawing analogies to the period leading up to World War II, when American Jewry was silent in the face of Hitler’s rise to power.

“We have to worry what history is going to say about us,” said Rabbi Emanuel Feldman, who sat on the panel along with Halkin and O.U. Chairman Harvey Blitz.

Feldman suggested that some issues are so morally compelling they demand a public response even when the practical effects are nil, or even negative.

The resolution was adopted after debate on several proposed amendments, which differed primarily in the amount of leeway they allowed in determining when to take an opposing position in public.

One amendment, which dropped the “exceptional circumstances” language in favor of a broad mandate to publicly communicate “the views reflected in this resolution,” fell three votes short of the required two-thirds majority.

O.U. President Stephen Savitsky lobbied for passage of the more sweeping amendment, arguing that the “exceptional” clause would mire the board in debate over what qualifies as exceptional.

But the original language prevailed, reflecting a compromise between a widely perceived need for the union to take a public stand and the organization’s longstanding policy.

“I think the process worked,” Luchins said. “I think the center held.”