1) Israelis are mostly Caucasians (whites) while the Arabs are non-Caucasians (non-whites). A liberal will always choose the non-white over the white group in a conflict. Even if the non-white group expresses murderous rage (as in the case with the Arabs) against the white group, liberals will always choose the non-white group.
2) Israel was formed a little over 50 years ago. In that time, Israel has become the most powerfu and well-developed l nations in the region and more powerful than most countries around the world. Meanwhile, the Arab nations that surround this country continue to live in squalor and have contributed nothing for centuries.
Here's the trigger that drives liberals with utter hatred toward a country barely the size of New Hampshire: The implication from the above paragraph is that Israelis (Caucasians) are smarter than the Arabs (non-Caucasians). Whether or not this is accurate is irrelavant, but the implication is there. Thus, the need to jutsify Israel has an "evil" country, even though it's surrounded by 200 million Arabs that wish it destroyed.