It was by UN resolution that Israel was created. That was rejected by the Arab World and the rest is history. I point this out because those opposed to Israel often point to UN resolutions to protest current Israeli actions, but fail to note the UN resolution that created Israel.
So the blame game is unhelpful; its too bad a pragmatic solution to the Israel/Palestine conflict was not worked out 30 years ago; back then, that might have stemmed some of the current upheaval. But the problems of the MidEast have morphed into something new and I am not certain that a just peace between Israel and Palestine would solve current West/Islam and Shiite/Sunni antagonisms. But, it would be a good start. It is true that the boundaries drawn by colonial powers, and past interference by the great powers (the US installing the Shah in Iran and the British and then the Russians in Afghanistan) explains much of today; but no solution rests in dissecting this history. We need pragmatism