The Hebrew phrase tikkun olam—“fixing the world”—has come to be one of the most well-known concepts in American Judaism, cited even by the President. In the Talmud, the term refers to adjustments in Jewish law made to benefit the workings of society. Medieval and Renaissance kabbalists then reinvented the term to refer to a mystical correction of the cosmos. In the 20th century, the term took on a whole new life, becoming a catchall for social and political activism usually of a leftwing variety. Jonathan Krasner surveys the history and examines what it says about the evolution of Judaism in America:

Even in its recent incarnation, tikkun olam is a highly flexible concept. In the 1930s and 1940s, it was invoked in order to show the harmony between Americanism and Judaism and to demonstrate the patriotism of an insecure immigrant community. In the late 20th century, it . . . could be invoked with equal vigor and to great effect by Jewish environmentalists and feminists, community organizers and peace activists. . . . It was social justice—Jewish-style—akin to wrapping the winter solstice in Hanukkah gift paper. . . .

The secret of the rise of tikkun olam was its power to give meaning to Jewish identity by reinforcing liberal political and social values that were already deeply ingrained in the vast majority of American Jews. Most Jews had a vague sense of correlation between their Judaism and their liberalism. Tikkun olam legitimized it and gave it a name. Tikkun olam promises much and demands comparatively little in the way of sacrifice. This is its greatest strength and, perhaps, its major weakness.

Two extraordinary events demonstrate something important about Israel’s most fervent adversaries. One was a speech given at something called The People’s Forum (funded generously by Goldman Sachs), which stated, “When the state of Israel is finally destroyed and erased from history, that will be the single most important blow we can give to destroying capitalism and imperialism.”

The suggestion that this tiny state is the linchpin of a global, centuries-old phenomenon like capitalism goes well beyond anything resembling rational criticism. Even if Israel were guilty of genocide, apartheid, and oppression—which of course it is not—it would not follow that its destruction would help end capitalism or imperialism.

The other was an anti-Israel protest that took place in front of New York City’s Memorial Sloan Kettering Cancer Center, deemed “complicit” in Israel’s evils. At organizers’ urging, participants shouted their slogans at kids in the cancer ward, who were watching from the windows. Given Hamas’s indifference toward the lives of Gazan children, such callousness toward non-Palestinian children from Hamas’s Western allies shouldn’t be surprising. The protest—like the abovementioned speech—deliberately conveyed the message that Israel is the ultimate evil and its destruction the ultimate good, cancer patients be damned.

The fact that Israel’s adversaries are almost comically perverse does not mean that they can be dismissed. If its allies fail to understand the obsessive and irrational hatred that it faces, they cannot effectively help it defend itself.