I don't think there is actual enmity between Jews and Christians. Historically (and I am talking about hundreds of years ago) there was a line taken by some Christian leaders that "The Jews murdered Christ". Given all the other baggage that the Christians attached to the passion, that's a bit rich. The real religious antagonists at the moment are the Shia and Sunni Muslims (both of whom hate the State of Israel too).
In the early church, Christians blamed the Jews for killing Jesus. Although it has eased today, it still has some bias lurking. Odd thing is, without the death of Jesus the Christians would have no basis for their "salvation" belief.