1. The Balfour Declaration
November 2, 1917: Foreign Secretary Arthur James Balfour writes a letter to Britain’s most prominent and influential Jewish citizen, Baron Lionel Walter Rothschild, expressing the British government’s support for a Jewish homeland in Palestine.
Britain’s public acknowledgement and support of the Zionist movement emerged from its growing concern surrounding the direction of the First World War. By mid-1917, Britain and France were in stuck in a deadlock with Germany on the Western Front, while efforts to defeat Turkey failed.

2. Motives for Britain to publicly support:
genuine belief in the righteousness of the Zionist cause
Britain’s leaders hoped that a formal declaration in favour of Zionism would help gain Jewish support for the Allies in neutral countries, in the United States and especially in Russia, where the powerfully anti- Semitic czarist government had just been overthrown with the help of Russia’s significant Jewish population.
Britain wanted dominance in Palestine—a land bridge between the crucial territories of India and Egypt—an essential post-war goal. The establishment of a Zionist state there—under British protection— would accomplish this.
Self-determination for smaller nations.

3. November 2nd 2017 marked the100 anniversary since Britain's Foreign Secretary Arthur Balfour issued the Declaration to establish a national home for the Jews in Palestine.
The Balfour Declaration forms the cornerstone of the Zionist design. They have relied on it as if it were a document of title to Palestine. It is often regarded as Britain's greatest allowance to political Zionism.
Although the document in its draft stage was amended and endorsed in Washington by supreme judge Louis Brandais and President Woodrow Wilson it took its name from the British foreign secretary who finally signed it.

4. There was notable opposition to the Declaration in the cabinet of Prime Minister Lloyd George. Lord Curzon warned of the consequences of issuing a deliberately ambiguous statement that would allow the interpretation that a Jewish 'state' was a possibility.
During 1919, an official US investigation into the conditions existing in certain parts of the former Ottoman Empire led by Henry King and Charles Crane found that "...the erection of such a Jewish state cannot be accomplished without the gravest trespass upon the civil and religious rights of existing non-Jewish communities in Palestine."

5. 1917, a vigorous anti-Zionist movement within Parliament held up the progress of the planned declaration.
Led by Edwin Montagu, secretary of state for India and one of the first Jews to serve in the cabinet, the anti-Zionists feared that British- sponsored Zionism would threaten the status of Jews who had settled in various European and American cities and also encourage anti-Semitic violence in the countries battling Britain in the war, especially within the Ottoman Empire.
This opposition was overruled, however, and after soliciting—with varying degrees of success—the approval of France, the United States and Italy (including the Vatican) Lloyd George’s government went ahead with its plan.

6. The influence of the Balfour Declaration on the course of post-war events was immediate:
According to the "mandate" system created by the Versailles Treaty of 1919, Britain was entrusted with the temporary administration of Palestine, with the understanding that it would work on behalf of both its Jewish and Arab inhabitants.
Arabs, in Palestine and elsewhere, were angered by their failure to receive the nationhood and self-government they had been led to expect in return for their participation in the war against Turkey.

7. In the years after the war, the Jewish population in Palestine increased dramatically, along with the instances of Jewish-Arab violence.
The area’s instability led Britain to delay making a decision on Palestine’s future. In the aftermath of World War II and the terrors of the Holocaust, however, growing international support for Zionism led to the official declaration in 1948 of the State of Israel.