Roz Rothstein | Jerusalem Post | May 17, 2026
Antisemitic conspiracy theories have deep historical roots and continue to resurface, driving prejudice and violence against Jews today.
Many people have never heard of Simon of Trent (Saint Simon), a Christian child born in Italy, whose disappearance and death in 1475 were falsely blamed on the Jewish community. Nearly a dozen Jewish men were immediately executed, and the blood libel spread far beyond Italy into Germany and across Europe, fueling persecution, expulsions, and inciting hatred against Jewish people for generations.
Nor have most people heard of another infamous antisemitic conspiracy theory: the accusation that Jews poisoned wells during the Black Death in the 1300s. Across Europe, Jewish communities were tortured, burned alive, expelled, or massacred after being falsely accused of causing the horrific pandemic.
These lies did not remain confined to the Middle Ages.
Most people have never heard of the Ibn Mashal conspiracy myth that circulated in Morocco in the late 17th century, portraying Jews as exploiters of Muslims.
That narrative fueled antisemitic suspicion and demonization of Jews, which, as so often happens, eventually contributed to violence and murder.
Blood libels and other antisemitic conspiracy theories resurfaced throughout history, including in Nazi propaganda, where they were weaponized to deepen hatred against Jews and justify persecution and mass murder.
And propagandists know exactly what they are doing.
They have always understood that if a lie is repeated often enough, it can shape public perception, fuel hatred, and eventually incite violence.
Hatred of Jews taught in schools throughout Middle East
In far too many places throughout the Middle East, including areas ruled by Hamas and the Palestinian Authority, antisemitic incitement against Jews has been documented in schools, media, sermons, and children’s programming. When children are repeatedly taught that Jews are evil or that violence against Jews is righteous, hatred becomes normalized across generations.
This is why Jews take dangerous lies about the Jewish people so seriously.
We call it antisemitism, and we confront it assertively because history has taught us what happens when lies about Jews are normalized, amplified, and repeated often enough. The pattern is tragically familiar: first come the accusations, then the bullying and dehumanization, then the violence.
We are witnessing this escalation again today, particularly in the aftermath of the October 7, 2023, Hamas massacres in Israel.
Jews have been targeted, isolated in ghettos, persecuted, expelled, and murdered repeatedly throughout history. Sometimes simply for existing, and other times because lies created mistrust, fear, and hatred that spiraled into deadly consequences.
That is why the antennas of the Jewish people are always up. There is a reason. There is a deep history.
Fast forward to today. Sensationalized stories and false accusations about Jews and Israelis do not exist in a vacuum.
Take the recent allegations in a The New York Times op-ed that included claims about Israeli dogs being trained to rape prisoners in Israeli jails. The article relied heavily on sources tied to Hamas or individuals with records of glorifying violence against Israelis. Yet even the most far-fetched accusations can spread rapidly because they reinforce narratives that too many people are already predisposed to believe.
Jews understand this dynamic. So do those who exploit it.
Some people wonder, “Why are Jewish people so sensitive about negative stories involving Jews or Israel?”
Because Jews have experience with the consequences of lies and demonization. We know that words matter. History has repeatedly shown that portraying Jews as monstrous or uniquely evil can and does lead to discrimination, violence, and even murder.
As Holocaust educators often remind us, “The Holocaust did not begin with gas chambers. It began with words.”
This principle should apply to everyone, not only Jews. Reckless hatred, dehumanization, and propaganda aimed at any group of people can have devastating consequences. We should all be more careful with our words and more willing to challenge dangerous falsehoods before they spread.
Nothing good comes from turning human beings into monsters in the public imagination. We must stand together against those who spread hateful propaganda and say, with conviction:
“Not on our watch.”
The writer is a daughter of Holocaust survivors. She is the CEO and co-founder of StandWithUs, a 25-year-old international organization that supports Israel and fights antisemitism through education.
