Though Balfour, himself, was in favor of a Jewish state, Great Britain particularly favored the declaration as an act of policy. Britain wanted the United States to join World War I and the British hoped that by supporting a Jewish homeland in Palestine, world Jewry would be able to sway the U.S. to join the war.
Though the Balfour Declaration went through several drafts, the final version was issued on November 2, 1917, in a letter from Balfour to Lord Rothschild, president of the British Zionist Federation. The main body of the letter quoted the decision of the October 31, 1917 British Cabinet meeting.
This declaration was accepted by the League of Nations on July 24, 1922 and embodied in the mandate that gave Great Britain temporary administrative control of Palestine.
In 1939, Great Britain reneged on the Balfour Declaration by issuing the White Paper, which stated that creating a Jewish state was no longer a British policy. It was also Great Britain's change in policy toward Palestine, especially the White Paper, that prevented millions of European Jews to escape from Nazi-occupied Europe to Palestine.