This discussion is a conflation of a civil discussion about the rights and responsibilities of a sovereign nation that happens to be named "Israel", as opposed to an ecclesiastical discussion about the role and meaning of Biblical Israel in the eyes of God. Combining those things is likely to lead to murky waters.
At the moment, the civic debate seems to be the more interesting one, and I'd like to weigh in some.
First, the religion of the various combatants is not particularly relevant. Whether they are Christian, Jewish, Muslim, Atheist, or worship my cats (they're so cute!), they are all human beings. There's been discussion about how one side or the other may be killing Christians, but I can't discern any Biblical reason why killing a Christian is any worse than killing someone who is not a Christian.
Second, a question to provoke thought: At what point do the Israelis have the right to defend themselves? The current UN condemnation actually states that Israel's actively being attacked with missiles (not under dispute)
is insufficient justification for self-defense (I'll hunt down a link if necessary; it was a couple months ago). I also have yet to hear an argument from Israel stating that it has the right to kill Palestinians for religious reasons. Generally the refrain over there has something to do with, "The ****ers are shooting missiles at us all the time." And, while the UN doesn't see that as sufficient justification for military action, I do.

And, I expect most Americans would as well, if America were the target.
That is not, of course, to say that Israel is guiltless. But, I do tend to support a stalwart ally in the region committed to the freedom and defense of its people.