To add to that, things are very different outside the U.S. In Europe, orthodoxy is still- nominally at least, the dominant player, though we in the UK and France live in a far more secular environment overall. Jews in the UK are increasingly seeking to identify in ways other than through the synagogue. There is the enormously successful Limmud study festival that takes place over Christmas, and is now a UK Jewish community export to the USA and elsewhere. There is an embryonic but successful move towards a JCC for London, with a site acquired and programs running, including a Mitzvah Day that attracts huge support, an important import from the U.S. to the UK. Official numbers of the Jewish population look astonishingly low in the UK given the numbers who attend Jewish Book Week or the Jewish Film Festival.

There is a new generation of young, vibrant, less traditional leaders across the community, and a sense that Jews are choosing to identify rather than being forced to do so by circumstances and birth.

That is really the nub of the question. In western liberal democracies, no one is forced to be anything specifically religiously speaking. So the fact that people are choosing to identify, whether through Limmud, Jewish Book week, through sending children to a Jewish school, an astonishing 1 in 4 of Jewish children, or more traditionally, through synagogues, is something of a triumph. We must be doing something right.

But how people choose, and what they will do, will change. I suspect that fewer people will join synagogues in the traditional way, but will instead pick and choose what they do and what they attend. The JCC will act -- as it does in many U.S. cities -- as a kind of portal. People will use it to make their choices, and they will vary according to their stage in life, the extent to which the community offers things they want, and the extent to which the community is prepared to recognize, accept and rejoice in a whole variety of different lifestyles. That will include people whose adopted children are not Jewish by status, but who will not want a full conversion for them, people who are gay and want to have a religious blessing of their civil unions, and people whose lives have been marked by a series of monogamous relationships, but find themselves living on their own in later life- in a pattern quite different from the conventional Jewish family pattern.

My own belief is that the community will adapt. It will also need to learn to cry antisemitism less often, and to trade on its strengths, not on a sense of victimhood -- that is not an attractive way of describing identity.

Jewish communities are stronger than they have ever been, more vibrant, more varied, and allowing huge opportunities for expression. The real question is whether, in free societies, that is enough to make people feel they want to stay involved, or whether they will just disappear, and deny their Jewish identity or simply forget it.