In the days of the USSR, many a Knesset meeting was held to discuss hopes for a mass Soviet aliyah. Last week, the Knesset turned its attentions to the challenge of how to stop many Former Soviet Union (FSU) immigrants from leaving.

One in two Israelis who emigrate from Israel is thought originally to hail from the FSU. Last year, this meant that around 2,000 Russian-speaking Israelis alone left for America, and this was a slow year for emigration.

The received wisdom is that they have been leaving mainly for economic opportunities and due to security concerns in Israel. But in the Knesset one of Israel’s leading experts on emigration dropped what policymakers will consider a bombshell.

Dov Maimon, senior fellow at the Jerusalem-based Jewish People Policy Institute, said that Israel has failed to make the migrants feel an affinity to the state. “This is the main reason that they leave the country — even more than financial difficulties,” he told the Knesset Committee for Immigration, Absorption and Diaspora Affairs.

Israeli policymakers are resigned to the reality that the volatile security situation will see some citizens leave in search of a calmer life. But they will be disturbed by the idea that the emigration phenomenon results from their failure to make migrants feel Israeli — after all, one of the country’s greatest sources of pride is its effective absorption of migrants.

Dr Maimon’s research tells a difficult truth. In the euphoria of the fall of the Iron Curtain, Israel glossed over the challenge of how it would integrate the many thousands of immigrants who were making aliyah under the Law of Return but who had no connection to the Jewish community or Judaism apart from one Jewish ancestor, and who, in many cases, followed another religion. It hoped that they would develop for themselves a national Israeli identity, and quickly gel with the Jewish majority.

But Dr Maimon says: “Immigrants without religious or ethnic Jewish roots, are not very accepted by the general Israeli society, even by the secular parts of it, and have difficulty feeling part of it”. Alienated by their lack of Jewish identity, these people are the most likely to leave Israel, he has concluded.

For every FSU immigrant who emigrates, there are others who continue to feel alienated in Israel. Two decades after the mass aliyah of Russian-speakers began, the Knesset has received a stark reminder that their absorption is still far from achieved.