Writing in the WSJ, Judea Pearl has an interesting parse of how Obama's Cairo speech described Israel:
Mr. Obama's rationale for Israel's legitimacy began with the Holocaust, not with the birthplace of Jewish history. "The aspiration for a Jewish homeland," he said, "is rooted in a tragic history that cannot be denied." Who else defines Israel's legitimacy that way? Iranian President Mahmoud Ahmadinejad does. Iran sees Israel as a foreign entity to the region, hastily created to sooth European guilt over the Holocaust. Israelis consider this distortion of history to be an assault on the core of their identity as a nation.
An affirmation of "Israel's historical right to exist," based on a 2,000-year continuous quest to rebuild a national homeland, is what the region needs to hear from Mr. Obama. The magic words "historical right" have the capacity to change the entire equation in the Middle East. They convey a genuine commitment to permanence, and can therefore invigorate the peace process with the openness and goodwill that it has been lacking thus far.
It's a provocative point, although I'm doubtful that the Arab world is more sympathetic to an argument about Israel's historical right to exist than to the idea of a refuge for persecuted people. In any case, ultimately such arguments probably matter less than practical appeals to peace, prosperity, the return of land, and the like. (Pearl also might've given Obama some credit for responding forcefully to Ahmadinejad's deranged Holocaust denial, which was probably the real point of this passage.)