Arthur James Balfour was elected Prime Minister of the United Kingdom in 1902, successor to Prime Minister Salisbury, his uncle. He first became interested in the Jewish Question when Theodor Herzl negotiated with Joseph Chamberlain, the British Colonial Secretary, in 1902 -1903 about the possibility of Jewish settlements in the Sinai Peninsula. In 1905, his Conservative Party lost the elections.
In 1906 a meeting took place in Manchester between Chaim Weizmann and Lord Balfour, who was impressed by Weizman's personality. He asked Weizmann why Palestine - and Palestine alone - could be the basis for Zionism. "Anything else would be idolatry", Weizmann protested, adding: "Mr. Balfour, supposing I were to offer you Paris instead of London, would you take it?" "But Dr. Weizmann", Balfour retorted, "we have London", to which Weizman rejoined "That is true, but we had Jerusalem when London was a marsh."
Balfour's interest in Zionism was revived during World War I. In 1915, he returned to the coalition as First Lord of the Admiralty and was appointed Foreign Secretary in Lloyd George's cabinet in 1916. As Foreign Secretary, he signed the Balfour Declaration on the 2nd of November 1917.
In 1925, Balfour agreed to be a guest of honor at the opening of the Hebrew University of Jerusalem and visited Palestine, where he was greeted enthusiastically by the Jewish population, while the Arabs welcomed him with black flags. Balfour was impressed by the flourishing Jewish settlements, which he felt demonstrated the strength and vigor of the growing Jewish national home. In 1928, his anthology of speeches on Zionism was translated into Hebrew.
The reasons for Balfour's support of the Jewish cause have been widely debated. In his book about the Balfour Declaration, Leonard Stein referred to Balfour's sharp condemnation of Antisemitism. "It is a shame for Christianity how this people was treated." Balfour considered the establishment of a Jewish national home as an act of reparation and reconciliation.
The interest in the Zionist movement remained a tradition in the Balfour family. His nephew, Robert Arthur Lytton, 3rd Earl of Balfour, supported Youth Aliyah. In 1939, he offered his family property and his house as center for the education of Jewish refugee children from Germany. Balfour's niece, Blanche Dugdale ("Baffy"), worked in the Political Department of the London office of the Jewish Agency, alongside Chaim Weizmann.