In May, when Israelis were attacked by Hamas missiles from Gaza, the criticism from some voices within the American Jewish community seemed not only more intense but categorical, escalating very quickly from what Israel did to what Israel is. In many blue state cathedrals, it was no longer good enough for critics to call themselves “pro-Israel” and “pro-peace” or affirm their Zionist credentials while blasting Israel for real or supposed misdeeds. Echoing social justice talk, dozens of Jewish and Israel studies scholars defined Zionism as “a diverse set of linked ethnonationalist ideologies … shaped by settler colonial paradigms … that assumed a hierarchy of civilizations” and “contributed to unjust, enduring, and unsustainable systems of Jewish supremacy,” while the CUNY Jewish Law Students’ Association more concisely demanded “a Palestinian right to return, a free and just Palestine from the river to the sea, and an end to the ongoing Nakba.” This language effectively denied the need for a Jewish state, thereby declaring war not just on Israel’s existence but on modern Judaism as we know it.Within American Jewry, this surge in anti-Zionism openly targets the broad Zionist consensus the Jewish world developed after the Holocaust and the founding of the State of Israel—as well as the post-1990s Birthright consensus embracing Israel and Israel experiences as central Jewish-identity building tools. Admittedly, anti-Zionist Jews are a small fraction of American Jewry, wildly outnumbered by polls showing 70% to 80% of the American Jewish community supports Israel’s existence as a Jewish state. But at a time when 85% of American Jews also say that it’s “important” or “very important” for them to “stand up for the marginalized or oppressed,” it is no wonder that for many American Jews, especially those in public spaces, Israel has become the ball and chain that endangers their standing as good progressives. It is also no surprise that this threat to their cherished identities as “progressives” is met by a corresponding fury that leaves no room for reasoned argument about specific Israeli policies or actions.The anti-Zionists know exactly what they are doing, and what they are undoing. They are trying to disentangle Judaism from Jewish nationalism, the sense of Jewish peoplehood, while undoing decades of identity-building. In repudiating Israel and Zionism, hundreds of Jewish Google employees rejected what they call “the conflation of Israel with the Jewish people.” The voices of inflamed Jewish opponents of Israel and Zionism are in turn amplified by a militant progressive superstructure that now has an ideological lock on the discourse in American academia, publishing, media, and the professions that formerly respected American Jewry’s Zionism-accented, peoplehood-centered constructions of Jewish identity.We call these critics “un-Jews” because they believe the only way to fulfill the Jewish mission of saving the world with Jewish values is to undo the ways most actual Jews do Jewishness. They are not ex-Jews or non-Jews, because many of them are and remain deeply involved Jewishly, despite their harsh dissent. Many un-Jews are active in forms of Jewish leadership, running Jewish studies departments, speaking from rabbinic pulpits, hosting Shabbat dinners. For many of these un-Jews, the public and communal staging of their anti-Israeli and anti-Zionist beliefs appears to be the badge of a superior form of Judaism, stripped of its unsavory and unethical “ethnocentric” and “colonialist” baggage.In launching this attempt, these anti-Zionists join a long history of such un-Jews, who wormed their way deep into the tradition and tried to weaken Jewish identity ideologically from within by canceling a central pillar of contemporary Jewish identity, as part of what they imagine to be a wider commitment to world liberation. This phenomenon of the un-Jews has emerged most dramatically whenever Jews sought to join with non-Jews in advancing quintessentially Jewish ideas of brotherly love, equality, and social justice, unmoored from their Jewish context and their Jewish delivery systems (historically, the most successful of these un-Jewish movements being Christianity).A century ago, when Zionism was still a marginal movement, and there was no Israel, Jews nevertheless had a strong sense of Jewish solidarity, of peoplehood. The base of what we remember as the shtetl was the kehilla, the rich, multidimensional, Jewish communal infrastructure.Those Jews who wanted to join the global communist revolution to change the world felt that they had to prove themselves by denouncing their people still living in their shtetls, their small, cloistered Jewish communities. One archetypal such Jewish radical was the German Marxist Rosa Luxemburg. Swept up by what we could call the critical class theory of her day, seeing the entire world through the Marxian lens of class struggle in the hope of bringing equality to all, Luxemburg, like many Jews of her day, was happy to jettison her Jewish particularism to fulfill her universal vision.In 1917, her friend Mathilde Wurm mourned the pogroms menacing their fellow Jews. “I have no room in my heart for Jewish suffering,” Luxemburg seethed. “Why do you pester me with Jewish troubles? I feel closer to the wretched victims of the rubber plantations of Putumayo or the Negroes in Africa ... I have no separate corner in my heart for the ghetto.” Some radicals even deemed the pogroms and other Jew-bashing outbursts necessary chapters in the “class struggle”—the violent birth of a new and better world.These Jews were following the cues from Karl Marx himself. In his infamous 1843 essay “On the Jewish Question,” Marx, the grandson of a rabbi, wrote: “What is the worldly religion of the Jew? Huckstering. What is his worldly God? Money … In the final analysis, the emancipation of the Jews is the emancipation of mankind from Judaism.”Executed by German anti-communists in 1919, Luxemburg didn’t live to see what happened when her noble ideas about equality were spread brutally, with no balancing ideals, by dictators and police states. As Soviet communism turned more repressive after the Bolshevik Revolution, it naturally recruited un-Jews to torment their former co-religionists. The Evreyskaya Sekcia—Jewish Section of the Communist Party—took special glee in freeing the Jews from the shackles of religion, of peoplehood, of community, of tradition. Believing their traditional communities to be as burdensome to them in much the same way that woke Jews feel Israel is burdensome to them today, these Jewish communists destroyed the synagogues and cheders they had been raised in to advance the Jewish idea of social justice which they first encountered in those spaces.Ultimately, the fire of revolution consumed these un-Jews too: Josef Stalin killed many of them, after they did his dirty work. Some of the survivors lived long enough to see their ideals collapse into the rubble of dictatorial repression, including Jew-hatred, which propelled many of their children and grandchildren back to the sense of Jewish peoplehood the founders sought to destroy in order to build their better world.The Soviet revolutionaries weren’t the first un-Jews to indulge in messianic self-harming—cutting out an essential part of contemporary Jewish identity in order to join the movement of the moment rebuilding humanity on more equitable and just foundations. Throughout the Middle Ages, Jews who were anxious to save the world by spreading Jesus’ teaching about peace and brotherly love often bullied their fellow Jews to leave their selfish superstitions behind and join them in this love crusade. True, Jewish-born persecutors of their fellow Jews like Pablo Christiani from the 1263 Disputation at Barcelona and Geronimo de Santa Fe from the 1413-14 Disputation of Tortosa converted. But their intimate knowledge of Jewish theology and Talmud, and the zeal with which they turned the knowledge against other Jews, suggested both that they were working hard to prove themselves to their new faith communities and also that they had not entirely succeeded in cutting their ancestral ties.As with the communists, these medieval zealots had indeed absorbed essential Jewish teachings, while rejecting the seeming contradictions that in fact gave their old beliefs their strength. Fanatics for love, for equality, for social justice, need ideological counters to temper their extremism. Judaism’s dualities, its seeming paradoxes balancing universalism and particularism, freedom and identity, or, in today’s terms, liberalism and nationalism, have often functioned as ideological brakes, preventing purists from going too far with any one idea, no matter how noble sounding. The totalitarian mind cannot stand the tension—and can kill people who seem to stand in the way of the dictator’s march toward love or equality or justice; the democratic mind—and the traditional Jewish mind—delights in working out the dilemmas, without fully embracing or rejecting either pole.The clash between zealots for progress—or what some decided was progress—and Jewish traditionalism reaches back to the time of the ancients, too.There were many Jews during Greek and Roman times who wanted to advance these appealing civilizations, which seemed to be giving birth to a brighter future. The Roman pantheon of gods seemed so much more majestic, more worldly, than the Jews’ one jealous God. These rebels would be happy to keep Jerusalem and other Jewish sites as relics as they marched along the road to a better tomorrow—backed by the imperial power of the Roman legions.One of the Roman generals who helped raze Jerusalem and destroy the Second Temple may have been the first un-Jew. Tiberius Julius Alexander, the nephew of the leading Jewish philosopher Philo, “did not remain in his ancestral customs,” in the words of the ancient historian Josephus, a Jewish general who himself joined the Roman cause. Then, as now, those annoying Jews insisted on keeping their ghetto, their ethnonationalist state, if you will, and rejected the symbols of Rome’s more worldly multicultural empire.Historians ultimately don’t know that much about Tiberius. What we do know is that despite his Jewish roots, he was anxious to help the world become civilized like Rome—and he unleashed the Roman legions against Alexandria’s Jews when he was prefect of Egypt from 66 to 69 CE. All this was warming up for his greatest crime against his people, serving as Titus’ second in command in 70 CE when the siege of Jerusalem plunged his own people into exile for nearly 2,000 years. Today’s un-Jews remain as engaged with parts of their Jewish heritage, as appalled by other parts, and as anxious for acceptance, as their predecessors. Their undoing project doesn’t involve conquering the Temple in the name of civilization or converting the Jews to Christianity. Instead, they are divorcing the democratic State of Israel in the name of democracy and social justice. Today’s social justice warriors make war on Israel the same way that the Soviet communists made war on Jewish peoplehood and its institutions.This assault goes far beyond “hugging and wrestling” or “daring to ask hard questions” or giving Israel “tough love.” Our objections to these new attacks are not attempts to dodge the difficult dilemmas we do need to debate regarding peace and war, proportionality and morality, Jewish and democratic values—or occupation, clashing rights, and defensible borders. We intimately know the many efforts that Israel’s political establishment and military take to maintain their moral compass. We wish there were more forums—such as a Global Jewish Parliament—where Israelis could discuss these and other dilemmas with world Jewry.But we can only have those debates if we have empathy for one another and are willing to look out for one another. Ultimately, a broad, welcoming dialogue is important. But those who are set on denying the essence of Jewish peoplehood are rarely interested in the kind of respectful, mutual exchange that builds us all up. Rather, they are bent on destroying the most powerful force that has kept us together as a people through the ages—and without which they, too, will paradoxically wither away.