Turbocharged by social media, a long-debunked antisemitic conspiracy theory is back and helping fuel the sharp rise in anti-Jewish sentiment. What once lived on the fringes of the internet now widely circulates on major platforms and has been repackaged to delegitimize Israel, erase Jewish history, and dress ancient prejudices in the language of “science.” This particular claim increasingly shapes how millions understand geopolitics and identity.
Last week offered a vivid example. In his interview with United States Ambassador to Israel Mike Huckabee, Tucker Carlson demanded that Israeli Jews take genetic tests to prove their descent from ancient Jews who governed Israel thousands of years ago. Carlson was invoking the Khazar myth, the claim that the “real” Jews died out after the Romans destroyed the Second Temple in 70 C.E., and that modern European (Ashkenazi) Jews instead descend from a Turkic people who converted to Judaism in 805 C.E. Once propagated by David Duke, the former head of the KKK, the theory has found new life online.
Lo and behold, the DNA testing Carlson calls for has already been done, and it has conclusively refuted this conspiracy.
In a 2010 peer-reviewed study, Dr. Gil Atzmon and his colleagues found that the genetic proximity among European and Syrian Jewish populations, including Ashkenazim, is “incompatible” with the theory that Ashkenazi Jews descend primarily from converted Khazars or Slavs. Those findings have since been independently replicated many times, showing that the world’s major Jewish communities — Ashkenazi, Sephardic, and Mizrahi — share a common Middle Eastern ancestry dating back roughly 2,000 years.
The genetic record also aligns with well-known history. In 586 B.C.E., Nebuchadnezzar II destroyed the First Temple and exiled many Jews to Babylon. When Cyrus II conquered the Babylonian Empire in 539 B.C.E., he permitted their return to Jerusalem, where the Second Temple was built. Some Jews remained in Persia, while others resettled in Israel and eventually dispersed across Europe, North Africa, and the Middle East, forming the core of today’s Jewish diaspora communities.
DNA evidence corroborates this history. Atzmon’s study further found that Ashkenazi, Sephardic, and Syrian Jews are genetically closer to one another than to Iranian and Iraqi Jews, a “split” dating back roughly 2,500 years and “compatible” with the period when part of the Jewish population remained in Persia, while the rest returned to Israel.
That alone should be sufficient to put the conspiracy theory to rest. Still, there are two additional problems with the Khazar myth.
First, the archaeological record reveals a continuous Jewish presence in Israel, including Jewish cemeteries, synagogues, and artifacts dating back to the fall of the Second Temple in 70 C.E. These Israel-born Jews obviously do not descend from the Khazars of the Central Asian steppe. And the vast majority of Israeli Jews do not come from Europe anyway. Rather, they are from the Middle East and North Africa, two regions where even conspiracy theorists concede the Khazars never lived.
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Second, Jews have lived in Europe since classical antiquity. Emperor Claudius expelled them from Rome in 49 C.E., and Cicero defended Valerius Flaccus in 62 B.C.E. against charges of seizing Jewish gold — events that make little sense if no Jews lived in Europe before the Khazar conversion of 805 C.E. In 613 C.E., two centuries before that conversion, King Sisebut of Spain decreed that Jews must convert or leave. There are many other examples of Jewish communities across Europe long before the Khazars, further undermining the claim that Ashkenazi Jews descend from them rather than from the ancient Israelites.
When it comes to Israel, as with everything else, facts should still matter. But in a cultural environment that rewards outrage and algorithmic amplification over evidence, even settled science can be drowned out by noise. Pushing back on myths like the one above is the responsibility of every citizen who cherishes truth and moral clarity. The effort may well determine whether democracies can still distinguish evidence from fiction before digitally driven falsehoods deepen a rising tide of antisemitism, a disease that has all too often proved fatal to civilizations.
Roy K. Altman is a United States District Judge for the Southern District of Florida and the author of Israel on Trial: Examining the History, the Evidence, and the Law.