Here is a 15-minute talk by Ilan Pappe, an Israeli and professor at Haifa University, delivered at Northeastern University in Boston, November 19, 2006: The Cleansing of Palestinians. Pappe traces the Israeli campaign to expel Palestinians from Palestine to the very origins of the Jewish state. Zionism's two founding impulses were, first, to find a safe haven for the Jews (quite necessary and urgent in an era of pogroms in the late 19th century), and second, to redefine Judaism as a national movement. It is this second impulse that, according to Pappe, is used by the entire Israeli political elite to justify any action -- including individual and mass killing, rape and destruction of property -- in its ethnic-cleansing campaign; Pappe hopes to stir a movement to end this policy.
See also Ilan Pappe: Israeli Jewish myths and the prospect of American war
And on the other side, ILAN PAPPE... Advocate of Israel's Destruction;
and finally, for details on his books, interviews, etc., Welcome to the official website of Ilan Pappé
As you will see, there is intense debate (especially in Israel) over some of his historical interpretations, which I'm not in a position to judge (e.g., were the Camp David accords really designed to establish "two Bantustans"?). What he says in this 15-minute talk seems to me persuasive.