ROME — A decade ago, the Jewish communities in communist-dominated Eastern and Central Europe were generally written off as dying remnants of the pre-Holocaust past.

Forty years of communist restrictions — and decades more than that in what was then the Soviet Union — had compounded the devastation of the Shoah.

Most who openly identified themselves as Jews were elderly. Many other Jews chose to conceal or deny their Jewish identity. And others, particularly in the former Soviet Union, faced active persecution. To some observers, Jewish life in Eastern Europe was virtually a closed chapter.

The collapse of communism 10 years ago changed everything. The institution of religious freedom and the disintegration of communist-era taboos triggered social, cultural and religious Jewish revival.

Exact figures have not been compiled, but throughout Eastern and Central Europe, thousands of Jews, particularly younger people, have discovered, recovered or reclaimed long-buried Jewish roots and openly declared a Jewish identity.

That may be through a superficial public self-identification as a Jew, or by participation in study groups and secular Jewish activities, or immersion in traditional, religious Jewish life.

Such a scenario has happened in Poland, in the Czech Republic and Slovakia, in Hungary, in Bulgaria — even in the countries of the former Yugoslavia.

While hundreds of thousands of Jews have immigrated to Israel and elsewhere from the former Soviet Union, at least 70,000 of them have immigrated to Germany, radically changing the face of the Jewish community there.

In addition, hundreds of thousands have also stayed in Russia, Ukraine and other countries, reopening synagogues and schools, and rebuilding communal structures.

"Jewish communities in the region are throwing off the mantle of 'remnant' like a garment that no longer fits," says Edward Serotta, an American photographer and writer who has documented Jewish communities in Eastern and Central Europe since the mid-1980s.

"We've been calling them last Jews, but they're not acting like last Jews — with kindergartens, summer camps, schools, youth programs and even Web sites on the Internet."

The impact of those changes has extended beyond the former communist states.

The emergence of newly active Jewish communities in Eastern Europe, combined with the development of a new vision of a pluralistic continent freed of artificial East-West frontiers, has created new opportunities, conditions and challenges.

The new freedoms have opened up a world of choices. And the outcome of these choices is still far from clear.

Jews in former communist states may be throwing off the mantle of remnant, but it is still too early to predict whether the momentum of what many call a Jewish renaissance will carry through into the 21st century.

Indeed, much of the support and infrastructure for Jewish revival in former communist states has been, and still is, funded by foreign institutions such as the Ronald S. Lauder Foundation, the American Jewish Joint Distribution Committee and the Chabad Lubavitch movement.

"Jews in Europe today are, first and foremost, voluntary Jews. Their continued presence in European societies demonstrates a conscious personal commitment," says Paris-based historian Diana Pinto.

"They could just as easily disappear into anonymity, stop being Jews. And they are of course free to do so; it is one of their rights in a pluralistic democracy."

Pinto, in fact, espouses an optimistic vision of a Jewish future in Europe, one that links Jewish development with the development of post-Cold War civil society across the continent.

That outlook views European Jewry both as a positive, creative force on the continent and as a "third pillar" in global Jewish affairs, alongside the Jews of America and Israel.

With that vision in mind, at the end of May nearly 600 Jews from 39 countries converged on Nice, France, for the first General Assembly of the European Council of Jewish Communities.

"We are here to celebrate the pride and optimism of being Jews in Europe and being European Jews," the council's chairwoman, Ruth Zilkha, told the meeting.

"We are committed to building an exciting Jewish life as part of a new democratic and pluralistic Europe," she said. "We are at a very special moment of creation and vision."

Looming in the background, however, were dire predictions from pessimists like British Jewish scholar Bernard Wasserstein, who articulated his negative vision of the European Jewish future in a controversial book, "Vanishing Diaspora," published three years ago.

Citing drastically negative demographic statistics, thanks to a combination of assimilation, falling birth rates and mass emigration from the former Soviet Union, Wasserstein pooh-poohs the idea of a European Jewish renaissance.

He disputes the European Council's claim that 3 million Jews live in Europe. He puts the total at 2 million — and falling.

Within a generation or two, Wasserstein glumly predicts, "here and there pockets of ultra-Orthodox Jews, clinging to the tenets of the faith, will no doubt survive — a picturesque remnant like the Amish in the United States."

Jews throughout Europe have a bitter and frustrated awareness of the looming, unresolved challenges that may hamper Jewish development both within individual communities and in the world at large.

Primary concerns include how to deal with the divisions among Orthodox, non-Orthodox and secular Jews; how to make Judaism a relevant choice; how to approach the high intermarriage rate; and how to solve the crisis in Jewish leadership.

Many of the same questions face Jews in the United States. But European Jews face them against a different historical and physical backdrop.

Two-thirds of Europe's Jews were killed in the Holocaust, destroying centuries-old communities. Moreover, the East-West postwar divide effectively cut off Eastern European Jews from the rest of the Jewish world.

Many Jews in Eastern Europe still maintain what Polish sociologist Pawel Spiewak describes as an "idle" Jewish identity: They are aware of their Jewish identity but they are not interested in deepening or admitting it.

That is strikingly evident in Hungary, whose Jewish population is estimated at anywhere between 54,000 and 130,000.

Like other countries in the region, Hungary has experienced a visible Jewish revival. Still, only about 6,000, most of them elderly, formally belong to the Jewish religious community.

Jews active in community work warn that the momentum of the current Jewish revival may be endangered unless new, younger leaders are prepared to take up the reins.

Increasingly, international Jewish organizations are establishing training programs for teachers, lay leaders and fund-raisers.

The European Council of Jewish Communities promotes cross-border contacts, keeps track of new e-mail links and Jewish community Web sites, and helps arrange activities — including international singles weekends.

But will that be enough?

Experts say critical mass for Jewish continuity in former communist Europe may not be achieved until the children of today's emerging Jewish generations come of age.

"It is the young who will decide on the character of the Jewish community," said sociologist Spiewak. "The third generation, the children of those who chose to be Jewish" as adults "are the ones who will determine the picture."