When CNN contacted me and asked me to write an online piece explaining why Israelis are upset by Yair Netanyahu’s relationship with a non-Jewish woman from Norway, I was puzzled. Why would anyone care? For one thing, Yair and Sandra Leikanger, a student at Interdisciplinary Center Herzliya, were not exactly publishing wedding dates. Nor is the precise nature of their relationship clear; the Prime Minister’s Office denied any romantic relationship.But most importantly, romantic involvements between Jews and non-Jews are not exactly news anymore. I would guess that minimally, a million Jews around the globe are currently in some such relationship with a non-Jew. According to the recent Pew study, the intermarriage rate among non-Orthodox Jews in America is currently 71 percent, which means that more than four out of five marriages involving a non-Orthodox Jew are intermarriages.JTA writer Julie Weiner recently tried to get Rick Jacobs, president of the Union of Reform Judaism, to answer the question: Is there any value in articulating a communal preference for endogamy? Jacobs pointedly refused to answer. The best he could do was: “I, as a parent, would love to see as much Jewish commitment as possible. It’s possible if you marry someone Jewish; it’s possible if you marry someone not Jewish.”AS PUZZLED as I was by the CNN request, I quickly discovered that Yair’s love life was indeed a diversion for the Israeli media, and that the young couple – if that’s what they are – and the reaction in Israel were being gleefully reported abroad. So my next question was: Why would anyone in England or elsewhere care about the subject? I came up with two answers. First, the madefor- TV donning of sackcloth by various Orthodox politicians served to confirm what a racist, clannish people the Jews are, rejecting out of hand an attractive blonde foreigner simply because she does not happen to be one of us.But I think that there was perhaps a deeper reason as well for the glee. Europeans, who do not in general care much for Israel, sense that if the son of the prime minister of the “Jewish state,” who is always busy demanding that Israel be recognized as such by the Palestinians, and the grandson of an eminent Jewish historian, is dating a gentile, this is not good news for Israel. Why might that be? IN GENERAL, Israelis are among the most patriotic people in the world. And despite the seemingly endless threats with which they live, they are also among the most optimistic. If one were to plot all the developed countries on a graph, with the vertical axis fertility rates and the horizontal axis suicide rates, Israel would be all alone in the upper-left quadrant – truly a nation that dwells alone.As I mentioned last week, the birthrate among non-haredi Jewish women is by far the highest in the developed world, and when ultra-Orthodox women are added, it is almost a full child per woman higher than any other developed country.While environmentalists might bemoan that fact, David Goldman argues in How Civilizations Die (And Why Islam Is Dying Too) that fertility rates in developed countries, where children are an economic burden and not an asset, are a fair measure of national health. With the exception of Israel and the US, most of the developed world is headed towards demographic oblivion.Simply put, people have children, at least in part, because they believe they are inheritors of something that is worth preserving and passing on to future generations. Those who view their lives as having purpose want to transmit that sense of purpose. Those who see life as just something to be gotten through, hopefully with as many pleasant distractions as possible, are less likely to have children. The process of state-building and the necessity of defending the state with a citizen’s army have played a large role in the feeling of most Israelis that they are engaged in a historical project. But the state is a fact, and there are from time to time signs that the old Zionist ethos is not what it once was. The failures of the Second Lebanon War were largely failures of will, as a host of commentators, most powerfully Avi Shavit, noted at the time.ULTIMATELY, THE most powerful source of national will comes from a feeling of being representatives of “the Jewish nation throughout the generations,” as a religious IDF colonel with whom I spent a morning this week put it to me. Quite possibly the most important national service the haredim perform is to serve as a concrete symbol that there is something far more precious than gold or silver in being Jewish.That, I presume, is what Yair Sheleg meant, when he wrote at the time the government was contemplating giving up sovereignty over the Western Wall, that haredi students bent over their Gemara do more for the state than they would in the army, for they remain the sole source of unadulterated Jewish identity.Wonder and enchantment with the Jewish story is pretty much the only tool remaining for secular Jewish identity. How did a tiny and despised people survive two millennia cut off from their land – a solitary sheep among 70 wolves in the Talmud’s description? Why was every ancestor of any Jew living today, whether a great scholar or simple peasant, willing to give up his or her life rather than betray their people or their God? Does history record a greater miracle than the smallest of the nations returning to the same tiny sliver of land for which they had prayed for 2,000 years? We have just marked the 53rd anniversary of the famous Montreal debate in which Yaacov Herzog made mincemeat of the eminent historian Arnold Toynbee, who had labeled the Jews a “fossilized” people. All materialist explanations of history, from Marx to Toynbee, founder on the continued existence of the Jewish people, which is one reason for the vituperation of the materialist historians and Toynbee to dismiss the Jews as some vestigial holdover.Once, the Jewish story was far better known in Israel than today. Tanach, Jewish history and even Talmud were important elements in the initial educational curriculum of David Ben-Gurion.When I hitchhiked around the country with young Israelis in 1976, they knew every place’s name and its antecedents in Jewish history. No more.WHAT DOES the Jewish story – a sense of oneself as connected to a past and as part of the future – have to do with intermarriage? As it says in Pirkei Avot, “The task is not yours to complete, neither are you free to leave it off.” We are part of a chain that did not begin with us and will not end with us, unless we deliberately saw it off. When a Jewish man marries a non-Jewish woman, he ends a particular chain of ancestors going back, in many cases, over 3,000 years. That chapter of the Jewish story is closed, for his children will not be Jewish. The same is true, as a matter of statistics, if not Halacha, when a Jewish woman marries a non-Jewish man. Though halachically Jewish, according to all studies of intermarried couples, her children are overwhelmingly likely to intermarry themselves, and the homes in which they are raised are likely to be devoid of Jewish content.Indeed, sociologist Bruce Phillips, in a mid- 1990s study, found that only 14% of intermarried homes identified primarily as Jewish, and 60% of those homes had Christmas trees.The determination to marry another Jew is a commitment to continue the Jewish story. For those in whom the preciousness of Judaism burns the necessity of marrying another Jew is a matter of logic, as much as Halacha. To transmit a sense of historical mission – especially one that has often entailed a heavy price – to one’s children requires a home in which both parents are committed to that goal.There is nothing racist about choosing for one’s life partner one who shares one’s most precious values.Doing so is a powerful affirmation of those values.(That’s why most alienated young Jews today are more likely to choose based on physical attraction, shared political views or taste in movies, than based on religion – the former are important, the latter is trivial.) And any human being who is prepared to make the same commitment that our ancestors did at Sinai is free to join the Jewish people.True, the insistence on marrying only a fellow Jew may involve placing one’s connection to the Jewish people above one’s personal desires. As long as the Jews of Israel continue to view themselves as emissaries of the historical Jewish people, and not as isolated individuals, Israel will remain the healthiest of the nations.When we cease to do so, we will be in big trouble.The gentiles know that. So should we. The writer is director of Jewish Media Resources, has written a regular column in The Jerusalem Post Magazine since 1997, and is the author of eight biographies of modern Jewish leaders.