How did the conflict in israel and palestine emerge from competing national movements?

As the periodic bloodshed continues in the Middle East, the search for an equitable solution must come to grips with the root cause of the conflict. The conventional wisdom is that, even if both sides are at fault, the Palestinians are irrational “terrorists” who have no point of view worth listening to. Our position, however, is that the Palestinians have a real grievance: their homeland for over a thousand years was taken, without their consent and mostly by force, during the creation of the state of Israel. And all subsequent crimes — on both sides — inevitably follow from this original injustice.

From late 1940s to nowadays Israel is supported by USA and western states. Arabs were supported by Soviet Union and the eastern block to the 1980s. 

The answer is william henry harrison pursued and defeated british forces retreating into canada.