The Jews of Europe are once again in grave danger, but the real threat to their future is not quite what you might think.

While the wave of anti-Semitism sweeping the continent is indeed disturbing, there is a far more destructive force at work these days, one that places the continued existence of European Jewry in doubt.

It is the ailment of assimilation and the malady of intermarriage which are truly wreaking havoc in Jewish communities across Europe. And though they may not receive as much attention as an assault on a rabbi in the streets of Paris or the desecration of a cemetery outside Berlin, the blows which they strike are nevertheless more lasting and more painful, as well as more difficult to repair.

The fact of the matter is that with only a few exceptions, the Jewish communities of Europe are gradually shrinking in size, contracting quantitatively as a result of declining birthrates, aging populations and increasing numbers of young people who marry out of the fold.

According to demographer Prof. Sergio Della Pergola of the Hebrew University of Jerusalem, there were slightly more than 1 million Jews living in Western Europe at the start of 2002. Of these, nearly 80 percent could be found in France and the United Kingdom, home to Europe's largest and strongest Jewish populations.

Instead of worrying so much about educating Europeans to like their Jews, we need to start educating their Jews to better appreciate their Judaism.

Yet, despite a wealth of Jewish communal institutions and a plethora of Jewish organizations, both French and British Jewry have been steadily in decline.

A December 2002 study by the Jewish Agency's Institute for Jewish People Policy Planning found that the number of Jews in France fell from 535,000 in 1980 to some 500,000 in just two decades, a loss of over 6 percent.

British Jewry fared even worse. According to the Board of Deputies, the representative body for Jews in the UK, there were 430,000 Jews living in Great Britain in 1950, but just 283,000 in 1996. Or, as an item on their web site puts it, "Since the 1950s there has been a steady decrease in numbers so that by the 1990s British Jewry was approximately one-third smaller than it had been in 1950."

If anything, these trends are only likely to accelerate, as the negative factors behind the demographic crisis continue to consolidate. Indeed, in both England and France, the annual number of deaths in the Jewish community already exceeds the number of births.

It is therefore hardly surprising that in a lengthy article appearing in the 2002 edition of the American Jewish Year Book, Della Pergola estimated that, "French Jewry will experience a slow but steady decline from 520,000 in 2000, to 480,000 in 2020, to 380,000 in 2050, and 300,000 in 2080." Meanwhile, across the Channel, he wrote, "The Jewish population in the United Kingdom will decline to 240,000 in 2020, 180,000 in 2050, and 140,000 in 2080."

In effect, this means that within just 75 years or so, French and English Jewry will only be half their current size.

In smaller Jewish communities in Europe, the retrenchment rates have been even more pronounced.

Take, for example, Ireland, where the 1991 census found there to be 1,581 Jews. Today, the number is said to be approximately 1,000, marking a decline of over 50 percent in just a decade.

Soaring intermarriage rates have taken a toll as well, in some cases reaching as high as 80 percent or more, raising further questions about the viability of some European Jewish communities.

And even in countries where the numbers have remained fairly stable, such as Spain or Italy, or which have experienced growth, such as Germany, it is primarily due to an influx of immigrants from the former Soviet states, and not because of any inherent vitality within the local community itself.

This disastrous situation should be raising alarm bells throughout the Jewish world. European Jewry is slowly but surely disappearing before our eyes, melting away through a combination of ignorance, assimilation and intermarriage.

Inexplicably, though, Israel and American Jewish leaders prefer to focus on combating anti-Semitism, rather than Jewish ignorance, even as its victims are increasingly facing religious and ethnic extinction.

The result, of course, is catastrophic, as attention and resources are shifted to fighting a question of bigotry, rather than of survival. Soon enough, there may not be any Jews in Europe left to hate.

Now don't get me wrong -- I am not trying to downplay the severity of European anti-Semitism. But when compared to the threat posed by assimilation, should it really be placed at the top of the agenda?

Instead of worrying so much about educating Europeans to like their Jews, we need to start educating their Jews to better appreciate their Judaism.

There is so much that can and should be done in this regard, from sending more rabbis to serve European Jewish communities to translating more material on Judaism into the various European languages. But all this takes funds and energy and commitment, and there is a limited amount of these to go around.

Only by acknowledging the extent of the problem, and deciding to act, can world Jewry and Israel possibly salvage the situation. The first step in doing so is to recognize that as crucial as it might be to fight Europe's anti-Semites, it pales in comparison with engaging its Jews.

This article originally appeared in the Jerusalem Post.