In the 11th and 12th centuries, the center of gravity of Ashkenazi intellectual life was in northeastern France and the Rhineland, although it would gradually move eastward over the course of the subsequent centuries. But Rabbi Isaac ben Moses, who became one of the great medieval experts on Jewish law, was born around 1180 in the German frontier province of Bohemia, and later settled in Vienna—a city almost as distant from the Ashkenazi heartland. He is better known by the name of his major work Or Zaru’a, taken from the verse from the book of Psalms, “Light is sown for the righteous, and gladness for the upright in heart.” Tamar Marvin tells his story:

To its Jewish denizens, Bohemia was known by the unflattering moniker “the land of Canaan,” and so the Or Zaru’a terms his Slavic glosses l’shon Canaan, “the Canaanite language.” Bohemia was indeed something of a hinterland in the 12th century, with its best and brightest finding their way to Regensburg and Prague. It seems that Rabbi Isaac suffered from economic straits and possibly other misfortunates in his younger years; in any case, he was impelled to travel widely, his peregrinations taking him to a wide swathe of the medieval Ashkenazi world.

And it’s this that makes Rabbi Isaac such an important tradent of Ashkenazi traditions, [i.e.], one who is responsible for preserving and handing on the oral tradition. Isaac Or Zaru’a went everywhere, talked to everyone, and wrote it all down. Isaac sought his first teachers in Prague, [the Bohemian capital], and Regensburg [in nearby Bavaria], . . . and from there to Speyer, possibly Cologne, and Würzburg, followed by Paris and Coucy in France, acquiring teachers in each locale.

This unusually large and broad set of mentors gave Rabbi Isaac grounding in the full array of Ashkenazi learning. From the margins he burst onto the very center of cultural life. The fruit of these many wanderings and years of learning coalesced in Isaac’s magnum opus, the Or Zaru’a. It wasn’t just a belletristic (and comforting) name; Isaac had in him the touch of a poet.

Isaac’s most famous student, Meir of Rothenberg, is perhaps the premier figure in medieval Jewish jurisprudence, whose rulings have an enduring influence on contemporary practice.

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.