The Jewish people owes British Jewry a great debt. At a time of growing fear and confusion and even despair about rising anti-Semitism around the world, Jews in Britain offered a powerful model on how to fight back.

Like many Jews, I was riveted by the drama being played out in Britain, where a small Jewish community not previously known for its assertiveness challenged a leader who could have been the next prime minister and a political camp many had considered home. With growing admiration, I followed the op-eds and tweets and video clips from British Jews that exposed and denounced and, most effectively, mocked the Jew-hatred emanating from the left.

A Corbyn-led Britain, Jews understood, would create a public space in which Jewish admission would be conditioned on an ideological loyalty test on Israel. The result would be the end of Jewish self-confidence and of a healthy Jewish life in Britain – perhaps the end of a viable Anglo Jewry.

The Jewish pushback against Corbynism united British Jewry and isolated its far-left extremists, created alliances with prominent non-Jews and helped convince many non-Jewish voters that a prime minister Corbyn would be toxic for the UK precisely because he would be toxic for its Jews.

Whether consciously or not, British Jewry adopted the playbook developed a generation ago by the international protest movement to free Soviet Jewry, the Diaspora’s most successful war against anti-Semitism. For a quarter century, beginning in the 1960s, Jews around the world led a sustained campaign that, astonishingly, lost none of its vitality over the long years of struggle. If anything, the movement only grew in strength, its rallies drawing ever-larger crowds and attracting new supporters from within and without the Jewish community.

The same principles that guided the Soviet Jewry movement also animated British Jewry’s campaign against Corbyn. Here’s how Diaspora Jews succeeded a generation ago, and how British Jews succeeded now:

First, define the threat, regardless of its ideological source.

One of the challenges facing the Soviet Jewry movement in its early years was how to overcome the notion, widespread among many on the left around the world, that the Soviet Union, for all its “mistakes” under Stalin, still represented a humane alternative to the capitalist West. In those years, many Jews, including significant Israeli figures on the left and large parts of the kibbutz movement, regarded the Soviet Union much as it regarded itself, as the avant garde of “anti-fascism.”

In challenging Soviet communism’s claim to be humanity’s great hope, the Soviet Jewry movement was also challenging that sentimental Jewish attachment to the dangerous fantasy of a good Soviet Union. Whatever gratitude the Soviet Union had earned from Jews for helping defeat Nazism had long since been obviated by its state-sponsored anti-Semitism and the near-total destruction of Jewish life within its borders. In denouncing the Soviet Union as the ideological successor of Nazi Germany, the Soviet Jewry movement defined the enemy and left no room for equivocation.

Similarly, in describing the Corbyn-led Labour Party as “institutionally anti-Semitic” and Corbyn himself as an anti-Semite, British Jews resolved to fight Jew-hatred regardless of its source. British Jews understood that the great threat to their wellbeing now came from precisely the camp that had for generations largely defined British Jewish political identity.

Second, unite the Jewish community.

In 1964, Yaakov Birnbaum, a British Jew who had moved to New York, founded the Student Struggle for Soviet Jewry (SSSJ), launching the public protest movement. He recruited his first activists from the Orthodox Yeshiva University and from the Conservative Jewish Theological Seminary. Yaakov, whom I had the privilege of working with in those years, taught us, his young disciples, that the only way to save Soviet Jewry was by uniting klal Yisrael, the totality of the community of Israel.

That unity was far from perfect – most of the haredi world, for example, remained opposed to the protest movement. And the movement was at times deeply divided over tactics, especially the short-lived violence of the Jewish Defense League. But most of American Jewry did eventually come together, a communal solidarity that ensured the endurance of the protest effort.

In their campaign against Corbynism, Britain’s Jewish leaders kept the dividing line within the Jewish community to a bare minimum. The line didn’t run between left and right, Orthodox and Liberal, but between the overwhelming majority of the Jewish community and Corbyn’s Jewish apologists. Like the Soviet Jewry movement, which avoided a right-wing anti-communist tone and embraced both left and right-wing Jews, British Jewry’s case against Corbynism was immeasurably strengthened by those Jewish voices with credibility on the left.

Third, reach out to non-Jewish allies.

Once Jews summon the courage to define threat and publicly resist it, non-Jewish allies appear.

Decades of American Jewish alliance-building – with churches, minorities, labor unions – resulted in widespread support for the Soviet Jewry movement. Martin Luther King and other civil rights leaders routinely spoke out for Soviet Jewry. The post-Holocaust Christian-Jewish dialogue, derided by the more insular parts of the Jewish community, proved its value in the Soviet Jewry struggle: One of the movement’s first demonstrations was an interfaith fast of clergy. And an interfaith council for Soviet Jewry, initiated by the late Rabbi Marc Tannenbaum, expanded the struggle.

One of the leading skeptics of American Jewish outreach to non-Jews was a young New York rabbi named Meir Kahane. There are no friends for the Jewish people, Kahane warned grimly, at best alliances of expedience. Kahane despised the moral high ground of the Soviet Jewry movement, ridiculing its appeal to universal values of human rights and its insistence on a broad coalition that included liberals as well as conservatives. Kahane broke with the mainstream Soviet Jewry movement and launched his own campaign of anti-Soviet violence and formed cynical short-lived alliances with far-right anti-communist groups, and even with an Italian American organization that was a Mafia front.

The decisive repudiation of Kahane’s isolationist doctrine came in the mid-1970s, when Congress adopted the Jackson-Vanik Amendment, which tied American trade credits to the easing of Soviet restrictions on Jewish emigration. It turned out that the Jews weren’t alone after all, that some of our most passionate advocates were politicians like Senator Henry Jackson with barely a Jewish constituency, who were on our side because it was right. With Jackson-Vanik, the Soviet Jewry movement became an American cause.

Around that time, a young Moscow refusenik named Natan Sharansky publicly allied with Soviet democratic dissidents, including Andrei Sakharov. Many of Sharansky’s fellow refuseniks were appalled. Their struggle isn’t ours, they said. When Sharansky was arrested, some in the Jewish community – and in the Israeli government – initially abandoned him, arguing that he had compromised the refuseniks with his reckless alliance. Today, of course, we celebrate Sharansky as the symbol of the Soviet Jewry struggle.

When Jews participate – as Jews – in wider social efforts, they aren’t betraying Jewish communal interests, as some among us claim, but ensuring that we won’t fight our battles alone.

A similar dynamic was at work in the anti-Corbyn movement. Prominent Labour leaders, along with cultural figures like J.K. Rowling and John Le Carre, broke with Corbyn and stood with the Jews. When British chief rabbi Ephraim Mervis took the unprecedented step of warning about the danger of Corbyn-led Britain, the Archbishop of Canterbury, Justin Welby, publicly affirmed the legitimacy of his anxiety. This too was a result of decades of Jewish-Christian dialogue efforts.

Finally, maintain optimism and faith.

When I joined the Soviet Jewry movement in 1965, my father, who had lived under communism in Hungary, warned me: You’re wasting your time, you don’t know who you’re dealing with.

Logic was on his side. The Soviet Union – a nuclear power stretching from the Chinese border to Berlin – was the most formidable totalitarian empire in history. Why, indeed, would the Kremlin care about foreign pressure? In those years you could easily name the Soviet Jewry activists; most of the Jewish community was still largely indifferent to our cause. Why, argued my father, would the mighty Soviet Union bend to the will of a group of children?

Yaakov Birnbaum convinced me that the Soviet Union after Stalin had lost its self-confidence and was less impervious, more vulnerable to outside pressure. But most of all I was convinced by Yaakov’s faith in Jewish history. We would win because we were right, because no matter what had happened in the interim the Jewish people always prevailed, because it was inconceivable that the last great Jewish community of Eastern Europe would simply disappear. We would win because we believed we would win.

Sometime in those early years I asked my mentor how long he thought it would take to free Soviet Jewry. Without hesitating Yaakov replied: Twenty-five years. Which was exactly the span of time from the founding of the Soviet Jewry movement in 1964 to the fall of the Iron Curtain in 1989.

Today American Jews face dilemmas that were inconceivable a generation ago. Is the President of the United States a threat to American Jewry, unleashing demons of divisiveness and hatred, or is he a protector of Jewish interests? Or perhaps a combination of both? Should a Jewish presidential candidate be held accountable for forming alliances with progressives who traffic in anti-Semitism? Is anti-Zionism different from anti-Semitism, or is it this generation’s most ideologically potent expression of anti-Semitism?

However Jews choose to answer those questions, they need to be explaining their concerns to each other.

Instead, American Jews are losing the ability to listen to each other’s deepest anxieties. They are bitterly divided about who qualifies as an ally: Those who are credible allies for some Jews in the fight against anti-Semitism are, for other Jews, themselves the most dangerous anti-semites. American Jews can no longer agree on what constitutes an anti-Semitic threat, let alone how to fight it.

The struggle against anti-Semitism can bring out fear, divisiveness, demoralization, insularity, delusional thinking, an emphasis on lesser threats while downplaying greater ones. But confronting threat can also summon the Jewish people’s most noble qualities – courage and creativity and communal solidarity. From my frequent encounters with American Jewish communities, I believe that the mainstream longs to reestablish some minimal consensus on how to identify and fight anti-Semitism. To recreate that consensus, American Jews can begin by studying the example of British Jewry, and by recalling their own community’s historic achievement in leading the international movement that helped defeat the Soviet Union.