Horse-hockey.
It begins with the assumption that Zionism is right and ends by portraying everyone who disagreed as wrong and evil.
Nope. It begins by assuming that the Arab Nationalists agreed to the Zionist request for one sliver of the Middle East....
...which they did.
The Arab Nationalists got their independent Arab Nations; they must stick by the deal, and acknowledge Jewish Palestinian rightful sovereignty over Jewish Palestine's independent Nation: Israel.
A deal is a deal.
Secondly, it's naive to presume that Balfour wasn't playing the same game of divide and conquer with Zionists that you accuse other Arab leaders of playing with Arabs. The Balfour Declaration was a political bid to generate support for Britain among Jews around the world. It should not be seen as uniquely moral and all Britain's other dealings as deceitful or duplicitous. Rather, the Balfour Declaration was part of the same pattern of power politics and manipulation.
Thirdly, the article is biased in other ways. It's building a case, not letting the facts speak for themselves. Why mention Arab links to Hitler and ignore Jabotinsky's admiration and emulation of European tyrants and his cooperation or aspiration to cooperate with them?
Finally, at the root of the matter is the fact that Zionism and the institutions to make it a reality developed before Palestinian Arab nationalism. That is a fact, as it was a fact that Western European nationalism developed before Eastern European, African, or Asian nationalism. White Afrikaaner nationalism developed before Black South African nationalism or nationalisms. Does that mean that because the Whites got their state ideology and institutions off the ground first that the Blacks could justly be deprived of rights forever?
Scott McConnell makes good points in his recent Open Letter to David Horowitz on the Israeli-Palestinian Conflict.