From my perspective, there's only one cause, and that's rejection of the legitimacy of the Jewish state. It was rejected by the Arab states in the region before the establishment of Israel in 1948. It was rejected by Palestinian leadership on five successive comprehensive and internationally backed U.S.-sponsored peace proposals, beginning with Oslo but not ending with Oslo.
Until Palestinians can wrap their heads around and accept the legitimacy of a Jewish state as their neighbour, we are condemning the region to conflict.