Impact of Balfour Declaration

Zionists living in Britain, chief among them Chaim Weizmann, lobbied the British government for a statement in support of a Jewish National Home. In reward for Jewish support and as a result of Chaim Weizmann’s influence and diplomacy, the Balfour Declaration supported the establishment of a Jewish National Home in Palestine as British policy, while not prejudicing competing Arab claims.

The Balfour Declaration radically changed the status of the Zionist movement. It promised support from a major world power and gave the Zionists international recognition. Zionism was transformed by the British pledge from a quixotic dream into a legitimate and achievable undertaking. For these reasons, the Balfour Declaration was widely criticized throughout the Arab world, and especially in Palestine, as contrary to the spirit of British pledges contained in the Husayn-McMahon correspondence. The wording of the document itself, although painstakingly devised, was interpreted differently by different people, according to their interests.

Ultimately, the two undertakings of the Declaration were incompatible. Although numerous compromise plans were proposed over the years, Arab interests could never accept that establishment in Palestine of a national home for the Jews could be accomplished with preservation of the rights of existing non-Jewish communities, i.e., the Arabs. The incompatibility sharpened over the succeeding years and became irreconcilable. 

Source: http://www.palestinefacts.org/pf_ww1_balfour_impact.php