On Yom Kippur morning in Manchester, as families walked to synagogue draped in prayer shawls, the world's oldest hatred appeared again in its most modern form.

A car was driven into worshippers. A man leapt out wielding a knife. Two Jews were murdered. Four others were injured. He tried to breach the synagogue doors, where hundreds were gathered in prayer. He was stopped just in time.

The image will not leave me: a synagogue door holding back a massacre. Blood on the pavement on the holiest day of the Jewish calendar. The screams of children silenced by locked wooden panels.

We like to imagine that such scenes belong to Europe's past. They don't. They belong to our present.

The question that hovers is not only how this could happen in Britain, but what it says about the moral condition of our age. And the answer is uncomfortable.

“A society that cannot protect its synagogues cannot protect its schools, its churches, or its mosques.

This attack did not fall from a clear blue sky. For years, especially since October 7, 2023, Britain has allowed a parade of anti-Semitism to course through its streets and campuses — weekly marches where crowds chant for Israel's destruction, glorify Hamas, and intimidate Jews walking home. The rhetoric became normalised. Leaders hedged. Police tolerated. Universities equivocated. And when hatred is indulged, the fringe hears permission.

Israel's foreign minister, Gideon Sa'ar, accused the Starmer Government of failing to curb a "toxic wave of anti-Semitism". He is right. Platitudes after a massacre are not enough. Words of compassion do not stop knives. A state that cannot enforce the line against incitement is a state that has failed its Jewish citizens.

But let us widen the lens. Manchester is not only a British story. It is a story about the West, about what happens when democracies grow careless with the hatred in their midst. Islamist ideology, whether inspired by Hamas or ISIS, does not stop at borders. The car-as-weapon, the marauding knife, the fake suicide vest — these are signatures we've seen before. In Berlin, just days earlier, police arrested Hamas-linked suspects plotting a Yom Kippur gun attack on Jewish institutions. Pattern, not coincidence.

And if Australians think this is "over there", we are wrong. Here in Melbourne, two synagogues have been firebombed in the past year. An Israeli restaurant, Miznon, was stormed by a mob. Anti-Semitism has surged to levels unseen in our country's history. The line between "them" and "us" is illusory. The ideology that fuelled Manchester is the same ideology shouted on our streets, painted on our walls, and whispered into our classrooms.

So what do we do? Three things. First, crush the networks. Surveillance, proscription, and disruption must be relentless. Second, dry the swamp. Zero tolerance for incitement on streets, campuses, and online. No more excuses, no more winks. Third, protect Jewish life.

None of this is novel. But it requires urgency, and urgency is what has been lacking. The lesson of Manchester is not simply that anti-Semitism kills. The lesson is that democracies that wait, hesitate, or explain away hatred end up with funerals.

What haunts me most about that Yom Kippur morning is not just the blood, but the silence that preceded it. The quiet of a community at prayer, broken by an eruption of violence. That is what anti-Semitism always tries to do: to turn holiness into horror, to make Jews fearful of being Jewish.

But here is the deeper truth. A society that cannot protect its synagogues cannot protect its schools, its churches, or its mosques. Manchester is a warning siren not just for Jews, but for all who believe in the integrity of liberal democracy.

The door held in Manchester. Next time, it may not.

And that is why the question is no longer "what happened?" The question is whether we will finally act before the next synagogue door is tested.