David Gerbi returned to Libya this year after 40 years in exile to help the rebel movement overthrow Muammar Qaddafi. Libyans he worked with knew he’s Jewish and did not seem to mind—they called him the “revolutionary Jew”—but when he announced he wanted to restore Tripoli’s synagogue, an angry mob threatened him while he was there praying. He has since left the country again, fearing for his safety.

It’s a depressing story, but it isn’t surprising. Anyone who believes anti-Semitism—not opposition to Israeli policies, but outright hatred of Jews—isn’t rampant in the Arab world is kidding themselves.

It wasn’t always this way. Jews lived in Libya for thousands of years. They didn’t live there without incident, but they lived there. They lived throughout what is now the Arab world for thousands of years, and they lived in these places alongside an Arab majority for more than 1,000 years. The Arab world has been more bigoted against Jews in the last hundred years than it was at any time during the previous thousand.

If relations between Jews and Arabs were better in the past, they can be better again. But they aren’t getting better right now.