If anyone had suggested in May 1964, when students from Columbia University held the first demonstration for Soviet Jewry, that a mere 25 years later the Iron Curtain would rise, the governments beyond it fall and the Soviet Union itself vanish, he would have been considered mad.

In fact, the struggle ignited then was so successful that four decades later Jews must wonder what made it a success, and whether they are following in the footsteps of those who stood up for oppressed Jews, or of those who had previously failed to act when Jews were being killed for being Jews.

The success of the struggle had many technical causes. Among them: the shrewd use of limited resources, smart sloganeering — most memorably “Let my people go” — and a very efficient harmonizing of Jewish and non-Jewish leadership, most notably in the form of the Jackson-Vanick Amendment that linked America’s commercial relations with the USSR to the latter’s treatment of its Jews.

Still, the Soviet Jewry struggle’s deepest source of power was a simple, ancient, and little appreciated weapon: Jewish solidarity.

On the face of it, Jews had always stood by each other in moments of distress. Since antiquity Jews were redeeming Jewish hostages they had never met, often ones whose language they could not even speak. Yet that was always local, involving one community’s lobbying on behalf of, say, several dozen Jewish passengers on one seajacked vessel.

When it came to treating an entire country’s Jewish catastrophe, the weapon of Jewish solidarity was about as relevant as a Beretta pistol in the face of an armored brigade’s attack.

When Spain expelled its Jews, for instance, it was inconceivable that the secure Jews of the Ottoman Empire would pressure the sultan to come to their brethren’s rescue. When Cossacks massacred thousands of Jews in the Ukraine, the well-off Jews of Holland watched helplessly from afar. And when Maimonides received news of forced conversions in Yemen, he focused on advising the local community on how to maintain its faith, rather than on confronting its tormentors.

In fact, it wasn’t until the modern era that it even occurred to powerful Jews that it was within their ability — not to mention their duty — to fight the persecution of any Jew, at any time, in any place.

Scholars cite 1840 as the turning point when European Jewish notables, led by Sir Moses Montefiore, mobilized various governments to challenge the Damascus blood libel. In 1878, thanks to pressure from such newly confident Jews, the Berlin Congress delayed anti-Semitic Romania’s independence. And during the Russo-Japanese War, American Jewish banker Jacob Schiff punished the czar for his anti-Semitism by raising $200 million for Japan on Wall Street.

Still, all this effective Jewish solidarity collapsed abruptly a mere century after its emergence, when a fragmented and low self-esteemed American Jewry and a pathetically powerless Zionist Organization failed to even dent, let alone offset, the catastrophe of European Jewry.

It was this trauma and the guilt trip that came with it that more than anything else fueled Jewish solidarity’s finest hour.

Today, the struggle’s main accomplishment is seen, fairly enough, in its astonishing result, namely the complete unshackling not only of Soviet Jewry but even of Syria’s and Ethiopia’s, clearly an extension of that same accomplishment. Yet the struggle of Soviet Jewry also had another accomplishment — it involved diverse participation.

Never before had Jews from Australia and France, Argentina and Britain, Israel and Canada, Mexico, the United States and elsewhere rallied so unanimously, durably and efficiently around one mutual cause. Israel’s clandestine agency for contact with Soviet Jewry — Lishkat Hakesher —deployed hundreds of diaspora youngsters who would enter the USSR, meet secretly with refuseniks, and try to keep them spiritually and materially afloat, handing them a siddur, a matzah pack or a pair of jeans that could be sold on the black market.

At the same time, thousands showed up repeatedly at mass rallies across the free world, routinely picketed Soviet embassies and consulates, habitually harassed visiting Soviet officials and generally inspired the media to perceive the Soviet Union’s anti-Semitism as a major news topic.

Now, with the incredible success of that struggle behind us, it is tempting to sit back, relax and nostalgically recall Jewish solidarity’s finest hour, as if there were not only no oppressed Jewish communities (except Iran’s) but also no anti-Jewish evil empire.

If only it were so.

The sad fact is that the Jews are again facing an evil empire, one that whether through microphones, keyboards or gun barrels targets Jews daily. Today’s Jewish world knows where this empire lies, and knows who leads and inspires it. It also knows that its anti-Semitic audacity rivals not the Soviet Union’s, but Nazi Germany’s. Only it doesn’t do anything about it.

The sad fact today is that while we in Israel fight the bullets of anti-Jewish terror, our brethren abroad have yet to join their part of the battle, which would focus on the Arab governments that at best tolerate, at worst fuel, current-day anti-Semitism.

Recently, a Jewish woman — Tali Hatuel — and her four daughters, Hila (11), Hadar (9), Roni (7) and 2-year-old Merav were slain at short range with submachine guns, instantaneously robbing David Hatuel of his entire family, including what was to be his first son.

Call me hysterical, but to the best of my knowledge such Jew-targeting — which has become routine in Israel in recent years — has not happened anywhere in the world since the Holocaust. The Soviet Union, let’s remember, merely caged the Jews. It did not kill them: Not at short range. Not in cold blood. Not entire families.

As of this writing, diaspora Jewry has yet to picket one Arab League embassy, Palestinian Liberation Organization office, Syrian consulate or Saudi Arabian Airlines storefront demanding an end to the Arab media’s demonization of the Jews and glorification of their killers.

Who is the diaspora waiting for?

Amotz Asa-El is a columnist and editor for The Jerusalem Post, where this piece previously appeared.