Efraim Karsh has what can only be described as a brilliant rebuttal to all of those who claim that Israel's existence is illegitimate, that everything it has done is illegitimate, etc.: http://www.commentarymagazine.com/viewarticle.cfm/1948--israel--and-the-palestinians--annotated-text-11373.
The war against Israel's existence is very involved, and it is being fought on many different levels. Yes, there are military battles, but the Arabs and their allies on the left and in the MSM have come to realize that a large part of the war comes from shaping public opinion. Part of THAT battle involves changing, inverting or outright lying about facts. If you read Karsh's article, you will have some ammunition to respond to those who wish to see the end of the world's only Jewish state.