In Greece the hatred dates to the Islamic invasions -- as I said above Syria, Egypt fell at least partially because Oriental Christians (syriacs and Copts) and Jews both collaborated with the invading Arab armies (as an aside BOTH were correct for the first 150 years of Arab rule, under the Ummayyads - they were treated better than they were under the catholic-orthodox Byzantine rule. Things changed after the Abbassids and especially after the FAtimids came to power)
This was remembered, but the REAL, REAL source for Greek hatred of Jews was the fall of Constantinople and after that -- The Odessa pogroms of the early 1800s were a case in point. They were triggered because in 1821, during the outbreak of the Greek War for Independence, the Jews were accused of sympathizing with the Ottoman authorities and of aiding the Turks in killing the Greek Patriarch of Constantinople, Gregory V, dragging his dead body through the streets and finally throwing it into the Bosphorus
According to several accounts, after Gregory's death his body, along with those of other executed prelates, was turned over to the city's (Istanbul's) Jews, who dragged it through the streets and threw it into the seaMy opinion is that the Jews of Istanbul did this to their rivals, not out of religious tension but as the Orthodox millet was their rival in business and in currying the attention of the Sublime Porte. The Greeks would do as bad things to the Jewish prelates if they got the chance.
The Russian hatred of Jews dates to the Russian gobbling up of the eastern provinces of the Polish-Lithuanian commonwealth.
Remember that by 1780, nearly 60% of World Jewry lived in Poland-Lithuania and the bulk of these were gobbled up by Russia
The Russians until this time had next to no Jews, so their experience was zilch and there were no prejudice
Suddenly they had an influx of Jews who were smarter than the average peasant and richer. Prejudice grew. The Jews were persecuted by the Tsars with pogroms etc. and Jews either retreated (Orthodoxy, Hassidism) or assimilated (eg. Marx's father converted) or were seduced by communism, a philosophy that preached equality for all. The last had the effect of making people think communism was a Jewish conspiracy (it is ironic that people thought both that communism was a Jewish conspiracy and yet at the same time saw the Jews as rich moneybags! But prejudice is illogical)
God’s blessings on Jews often provoked jealousy. That’s it in a nutshell. When burning with jealousy, it’s easy to come to grandiose accusations.
Thank you for your two thoughtful and informative postings addressed to me (and others). Lots of interesting information in them.