I agree that it makes no sense to speak of anti-semitism around the time of Christ. At that point it is all sectarian friction. The Romans oppressed everybody. The crucial stage is the rise of Christianity in a feudal setting as an authoritarian economic/political/social/etc institution. It is in that period when the animus towards Jews and the supporting myths acquire permanent social weight. There was no less animus towards Islam in Christendom, I would imagine, but obviously jews had a special role in the story of the faith. Once let loose, the prejudice took on a life of its own, in the sense that it played historical roles in various contexts, such as today in Malaysia.
I remember reading a history of jews in Japan in the interwar period. They were regarded as exotic and potentially valuable allies. The Emporer's wise men were quoted as saying they would present him with a 'delicious dish,' in the form of the services of world jewry. Of course, when you're exotic you're also different and vulnerable.
Israel has had zero to do with the nature of anti-semitism, IMO. It's provided some extra detail for stores about the end of days is about all. Israel has had a lot to do, obviously, with the views of Moslems towards Jews, and that dovetailed with historic anti-semitism in certain ways. If the Jews had settled in Uganda instead of Palestine, I daresay the attitudes of Africans and Moslems would be roughly reversed, as far as anti-semitism goes.
It also seems to me anti-semitism is intrinsically about a malevolent, tiny minority. The point of view of the bigot is of a vast majority defined in some way. Another distinction from the early Christian era that works in a place w/o jews today, such as Poland or Asia.
mbs