In Modern Orthodox Judaism: A Documentary History, Zev Eleff for the first time has collected the source materials necessary to understand the development of a denomination that, although its adherents account for under 10 percent of affiliated American Jewry, now plays a disproportionate role in American Jewish life. Daniel Ross Goodman praises the book, while noting some serious gaps:

The history of self-consciously “modern” Orthodoxy is inseparable from the history of Yeshiva University, which is a product of the early 20th century. Eleff covers Yeshiva University’s birth, development, and evolution. . . . Of course, the book also contains several key statements from Modern Orthodoxy’s most outstanding spokesmen: the great halakhist and thinker Rabbi Joseph B. Soloveitchik, [the movement’s most prominent rabbi until his death in 1993], and Rabbi Norman Lamm, who served as the president of Yeshiva University from 1976 to 2003. . . .

Although Rabbi Lamm has been a central figure of inestimable importance to Modern Orthodoxy for nearly seven decades, graduates of Yeshiva University, and anyone even tangentially connected to the institution, are well aware of the fact that it has not been Lamm but rather Yeshiva University’s rashey yeshivah—authoritative halakhists and brilliant talmudists like Hershel Schachter, Mordechai Willig, [and others]—who have, arguably, had a more direct impact on the lives of thousands upon thousands of American Modern Orthodox Jews. It is surprising then, that a volume that features so many texts related to Yeshiva University all but completely excludes figures who can be said to have been the university’s most influential rabbis.

When it comes to Modern Orthodoxy’s present challenges, Goodman finds Eleff better attuned:

The ideology of Modern Orthodoxy, undergirded by Soloveitchik’s distinctive blend of existentialism and neo-Kantianism, is a difficult one to grasp. Most people prefer clear lines and black-and-white differentiations to living with complexity, and it doesn’t help matters that even many of those rabbinic leaders who understand Soloveitchik’s philosophy and embody its values, like Rabbi Lord Jonathan Sacks, do not identify themselves as Modern Orthodox.

This, combined with growing pressure from its right and left flanks, the prohibitive cost of Modern Orthodox life, widespread theological uncertainty, and a continuous “brain drain” in which many of the most committed American Modern Orthodox Jews leave for Israel—Modern Orthodox Jews have the highest rates of aliyah among all American Jews—means that the movement’s future will likely be as ambiguous and complicated as its complex, tension-filled philosophy.

Yasir Arafat was often quoted as saying that his “strongest weapon is the womb of an Arab woman.” That is, he believed the high birthrates of both Palestinians and Arab Israelis ensured that Jews would eventually be a minority in the Land of Israel, at which point Arabs could call for a binational state and get an Arab one. Using similar logic, both Israelis and their self-styled sympathizers have made the case for territorial concessions to prevent such an eventuality. Yet, Yoram Ettinger argues, the statistics have year after year told a different story:

Contrary to the projections of the demographic establishment at the end of the 19th century and during the 1940s, Israel’s Jewish fertility rate is higher than those of all Muslim countries other than Iraq and the sub-Saharan Muslim countries. Based on the latest data, the Jewish fertility rate of 3.13 births per woman is higher than the 2.85 Arab rate (since 2016) and the 3.01 Arab-Muslim fertility rate (since 2020).

The Westernization of Arab demography is a product of ongoing urbanization and modernization, with an increase in the number of women enrolling in higher education and increased use of contraceptives. Far from facing a “demographic time bomb” in Judea and Samaria, the Jewish state enjoys a robust demographic tailwind, aided by immigration.

However, the demographic and policy-making establishment persists in echoing official Palestinian figures without auditing them, ignoring a 100-percent artificial inflation of those population numbers. This inflation is accomplished via the inclusion of overseas residents, double-counting Jerusalem Arabs and Israeli Arabs married to Arabs living in Judea and Samaria, an inflated birth rate, and deflated death rate.

The U.S. should derive much satisfaction from Israel’s demographic viability and therefore, Israel’s enhanced posture of deterrence, which is America’s top force- and dollar-multiplier in the Middle East and beyond.