Parshat Balak seems to address the issue of anti-semitism. We see how Nations made an alliance against Israel that was motivated by their common hatred of the Jewish people. Bilaam was hired by Balak to curse Israel. Bilaam did not need much convincing as our rabbis tell us that he hated the Jews even more than Balak did.
Many people have a problem with the general rabbinic statement that עשו שונא את יעקב, Eisav, representing the Gentile, hates the Jew.
Jews are often accused of being paranoid in that we blame everything on anti-semitism. Aside from being justified in having that sentiment based on our long exile, we are cautioned to keep our eyes open, regardless of what appears to be very cordial relationships with non-Jews. And too often we refuse to accept this reality and are later proven wrong.
The only real hope is that in times of the Redemption, the nations of the world will not only change their attitudes about the Jews, but they will show real remorse for how we were treated throughout our history. Let us hope we are in that period of time.