It is the bane of much of world Jewry, a phenomenon growing worse with each passing year, one that poses a grave threat to the future of the entire Jewish people.
For the past few decades, scholars, activists and educators throughout the Diaspora have grappled with the challenge of soaring intermarriage rates, warning of the dire consequences for Jewish identity and continuity.
And while Israel had largely been immune to this peril, over the past few decades, new data indicates that may no longer be the case.
Last month, Dr. Netanel Fisher, head of the School of Public Administration, Governance and Law at the Sha'arei Mishpat Academic College of Law and Science, revealed a series of figures regarding intermarriage in Israel that should set off alarm bells.
Analyzing information he obtained from Israel's Central Bureau of Statistics (CBS), Fisher found that there are 85,000 intermarried couples in Israel in which one partner is Jewish and the other is not, representing 7% of all marriages in the country.
Since the CBS statistics do not include categories such as Israelis married to foreign workers without residency or citizenship, or couples living together, the actual numbers are almost certainly higher.
Moreover, it appears that the frequency of intermarriage is on the rise. Between 2011 and 2018, the intermarriage rate involving Israelis surged by 38%, from 1,527 to 2,460 cases per year.
As The Jerusalem Post reported: "The vast majority of intermarried couples in Israel, some 90%, involve a Jew and a citizen defined as 'without religious classification,' the large majority of whom are Israeli citizens born in the former Soviet Union or their descendants."
Some observers might be tempted to dismiss the significance of such intermarriages. After all, the child of a Jewish mother, regardless of the father's status or religion, is still Jewish according to Halacha.
But a deeper dive into the data leaves no room for doubt, as the majority of interfaith marriages in Israel are between a Jewish man and a non-Jewish woman. Nearly 60 percent, or 52,000 out of 87,000 intermarriages, involve a woman who is not Jewish. Consequently, their children will not be considered Jewish either.
This trend toward greater intermarriage is likely to continue, if only because a sizeable percentage of those who make aliyah each year under the Law of Return are non-Jews.
According to the Interior Ministry, between 2012 and 2019, 37% of all immigrants to Israel were not Jewish according to Halacha. And there are anywhere from 400,000 to 500,000 immigrants from the former Soviet Union who are not classified as Jews.
And since every single one of them lives and works here and is part and parcel of Israeli society, it is inevitable that many will end up marrying Jews.
While intermarriage in Israel will never reach the levels seen in the United States and various European countries, where figures range well above 50%, that is hardly a source of much comfort.
"If Jews in Israel thought intermarriage is only a challenge to communities abroad, we now know that intermarriage is also a challenge to Israelis as well," Fisher rightly noted.
There are of course numerous factors behind the rise in intermarriages in Israel, ranging from the failure of the educational system to inculcate a stronger sense of Jewish identity, to a conversion system that is overwhelmed, understaffed and underfunded. And there is plenty of blame to go around.
But in light of the gravity of the situation, this is hardly the time to engage in speculation or criticism. Instead, all of our energies and efforts should be directed toward finding solutions, because with each day that passes, the situation will only continue to worsen.
There are reasons to be hopeful. A recent survey released last week found that 45% of Russian immigrants who are not considered Jewish are open to the idea of undergoing conversion.
This indicates that a large portion of them feel a sense of connection to Jewishness and wish to tie their fate with the people of Israel. It behooves us as a society to reach out to them and do what we can to encourage their social, religious and spiritual integration, while of course maintaining the integrity and upholding the requirements of Jewish law.
Each night on Hanukkah, the dance of the flames on the candles reminds us of Divine providence and the miracle of Jewish survival. But each flicker also serves to underline just how fragile our existence can be.
And so, like the Maccabees of old, we must take bold action to strengthen Jewish nationhood and kindle the souls among us.
Nothing less than the Jewish character of Israel is at stake.