The Balfour Declaration of 2 November 1917 was issued shortly before the end of WWI. The declaration consisted of a letter from British Foreign Secretary Arthur James Balfour to Jewish community leader Baron Rothschild for transmission to the Zionist Federation of Great Britain and Ireland, reflecting the position of the British Cabinet about establishing a Jewish "national home" in Palestine. It was a very brief, non-specific policy statement:
"His Majesty's government views with favour the establishment in Palestine of a national home for the Jewish people, and will use their best endeavors to facilitate the achievement of this object, it being clearly understood that nothing shall be done which may prejudice the civil and religious rights of existing non-Jewish communities in Palestine, or the rights and political status enjoyed by Jews in any other country."
The conspicuous omission in this statement is any reference to the political rights of non-Jewish communities, which represented over 90% of the Palestinian population at that time.
Why was it written? The history of this document is rooted in the Zionist agenda from the turn of the 20th century to establish a Jewish homeland in Palestine. The American arm of the World Zionist Organization (WZO) was able to take advantage of WWI to opportunistically advance their agenda at enormous cost to their own country.
Under the 1916 Sykes-Picot agreement between France and England regarding division of Ottoman territories for post-war administration upon their anticipated defeat, England would be assigned administration of Palestine. But meanwhile, the WZO had their eye on Palestine since the turn of the 20th century, and was both motivated and able to cut a deal when the opportunity arose.
According to Col. T.E. Lawrence ("Lawrence of Arabia") who led Arab forces against the Ottomans in WWI upon British assurance that they would be granted their own countries under the British mandate should Britain prevail, the declaration was a quid pro quo to the WZO for "bringing America into the war" and financing the war effort when Britain was facing potential defeat under intensive German submarine attacks against incoming supply ships in early 1917. Thus Britain had promised the same land to two different allies, one already living there and one wanting to.
Despite Palestine's overwhelmingly non-Jewish population, London Zionist movement leaders Chaim Weizmann and Nahum Sokolow had requested reconstitution of Palestine as “the Jewish national home" and were disappointed at this weaker statement. Their disappointment notwithstanding, this declaration is frequently cited as the original legal authority by Zionists and their supporters for their seizure of Palestine by force, but of course the language shown in red text is never mentioned nor is the lack of any British legal authority to give anyone's land or property to anyone else.
During Woodrow Wilson's 1916 presidential campaign he pledged to keep America out of the Europen war. However, when the Zionist Organization of America learned that Britain had agreed to establish a Jewish homeland in Palestine should they prevail, the ZOA immediately sprang into action. Louis Brandeis, America's first Jewish Supreme Court Justice, was a member of a secret elitist Zionist society called The Parushim, in which each initiate was sworn by oath to secrecy and support of the Zionist project as their highest allegiance. Harvard law professor and future Supreme Court Justice Felix Frankfurter was also a member. Brandeis was a close friend of Woodrow Wilson with presidential access that he no doubt used to support American entry into the war, violating Wilson's campaign promise, that could bring about the Zionist goal. Over 116,000 Americans died in this war - twice those killed in Vietnam.
Wealthy Jewish-American financier Bernard Baruch, also an ardent Zionist, has been credited with orchestrating a sudden proliferation of anti-German propaganda (now "huns" who butchered babies) and a breakneck U.S. industrial mobilization for war that saved the day for Britain.
But the movement had a close call. Early in 1917 the Ottoman Empire gave indications that it might withdraw from its alliance with Germany and Austria-Hungary and negotiate a separate peace treaty. This would have avoided Ottoman defeat and obviated the anticipated British mandate with its promised Jewish homeland. The State Dept. dispatched a delegation under ex-Ambassador Henry Morganthau to explore this with the Ottomans. Felix Frankfurter was a delegation member, who selected other Zionists to complete the delegation. The British sent Zionist leader Chaim Weizman representing Britain to meet with the delegation in Gibraltar. Unsurprisingly, Weizman and Frankfurter persuaded Morganthau to scrap the mission.
The Balfour Declaration language was incorporated into the League of Nations mandate assigning Britain to administer Palestine during transition to independent statehood. To fulfill this pledge during the mandate period between world wars, Britain permitted heavy Jewish immigration increasing the Jewish population from one-tenth to nearly one-third of Palestine, which precipitated strong Arab resistance culminating in the Arab revolt of 1936-1939. British suppression of this revolt and disarming of the Arabs left them vulnerable to the ethnic cleansing by Zionist terrorism that ensued following WWII.