It started with the Jewish diaspora under the ancient Romans. After a series of Jewish revolts against Roman rule, Jews were not allowed to settle or worship in Jerusalem for 500 years. Only when the Muslims took Jerusalem were Jews invited back, but they were not given political power.

As a result Jews formed communities elsewhere in the Roman Empire. When Christianity became the official religion of the Roman and Byzantine empires, it created a tense relationship with Jews. The same was true in the Muslim empire. Throughout the Middle Ages, at times Jews were tolerated, and at other times they were persecuted.

Since they were often not allowed to own land, and their existence in any particular land was always subject to change, many Jews formed international relationships with fellow Jews in other countries, and took advantage of those relationships in trade and finance. This helped them survive and even thrive, but their success often made them even more of a target of discrimination.

They were, in short, a common and easily identified minority in every European and Middle Eastern country, at a time when there were few other minorities. There were some other minorities also subjected to discrimination. In fact, pretty much any outsider was suspicious. But none were more pervasive or visible than Jews. The fact that many were successful in business despite or even because of the discrimination just made the hatred directed at them more intense.

That remained the case in the 19th, 20th, and 21st centuries. Furthermore, as aristocrats lost power and capitalists gained power, it was convenient to deflect anger away from other capitalists by pointing the finger at wealthy Jews. That has continued to be the case throughout the West.

Of course, today there’s also the issue of the State of Israel, which has never really been accepted in the Muslim world. And Israel’s response to Muslim aggression has turned them into an occupying force that has been accused of human rights violations. In other words, in the one country run by Jews they treat Muslims as outsiders, and have been accused of unjustified discrimination against them. And since the U.S. backs Israel with massive military and economic aid, the U.S. is often blamed for Israel’s actions.