In 1912, after the 1908 Young Turks revolution, Ben-Gurion and a handful of other Poalei Zion activists went to study at the University of Istanbul - hoping to develop ties with the emerging elites and to change anti-Zionist Ottoman policies. His studies were cut short by the outbreak of the World War I while Ben-Gurion was on summer vacation in the Galilee. The following year, he was expelled from Palestine by the Ottoman government - together with other leading Zionist activists, including Yitzhak Ben-Tzvi (Israel's second president).
Arriving in New York in 1915, Ben-Gurion devoted the next two years to building an "American wing" to Labor Zionism. At this time, he met and married his wife Paula. Ben-Gurion initially opposed a Jewish military unit in the British army such as Jabotinsky's Zion Mule Corps, fearing it would jeopardize the Jewish community in Palestine. However, under the impact of the Balfour Declaration of 1917, he reversed his stand, joining Jabotinsky's call for the formation of Jewish battalions within the British army to liberate Palestine from the Turks. He himself volunteered, serving in Egypt in one of the three Jewish battalions - the 39th Royal Fusiliers.
In 1921, Ben-Gurion was elected secretary-general of the Histadrut, the General Federation of Labor founded a year earlier. He served in this capacity until 1935 - throughout the formative years of the Histadrut. Under his dominant and at times domineering leadership, the Histadrut created many of the social and economic institutions that would dominate Israeli society for decades to come. Long-winded meetings were the order of the day; when Ben-Gurion met opposition to his visions, he would present his position over and over - sometimes in a series of meetings - until the doubters were convinced, or at least exhausted into submission.
Thus, Ben-Gurion orchestrated the formation of the hevrat ovdim (workers' society), a network of Histadrut-run organizations and corporations that undertook expansion of cooperative agricultural settlement and infrastructure projects, developed industries and created cultural frameworks, health services and even financial institutions of its own. alongside the Histadrut's trade union functions, this network, in essence, supplied the infrastructure of a new society and state-in-the-making.
In 1930, Ben-Gurion played a central role in the amalgamation of major laborite factions into a highly-effective political machine - Mapai, a political party that would guide and govern Israeli society during the first critical decades of statehood, with Ben-Gurion at the helm. By 1935, Labor Zionism was the most important element in the World Zionist Organization, and Mapai was able to appoint Ben-Gurion to the key post of chairman of the Jewish Agency Executive - the settlement arm of the Zionist movement - a post he held until 1948, when the State of Israel was established.
Ben-Gurion was acutely aware of his place in history - documenting his moves in an enormous and orderly historical estate. His personal diaries alone run to hundreds of thousands of pages. Motivated equally by a desire for leadership and for learning, he was well-read - particularly in history and political and religious philosophy - his personal library encompassing some 20,000 volumes. A thorough individual in areas that captivated his curiosity, Ben-Gurion mastered Greek to read Plato in the original.
In the wake of Arab riots in Palestine, the 1937 Peel Commission proposed partition of Palestine, granting the Arabs the "lion's share" of Mandated Palestine left after the creation of Transjordan in 1922. World Jewry was thrown into turmoil. Yet Ben-Gurion, who viewed a tiny Jewish state as a foundation and fulcrum for realization of Zionist aspirations, mobilized all his influence and leadership to prevent rejection of the plan by the Zionist movement. While the Zionist leadership reluctantly accepted the plan, the British decided not to carry it out. The 1939 White Paper - which restricted Jewish immigration and the rights of Jews to buy land in Palestine - was seen by Ben-Gurion as an outright betrayal of the Balfour Declaration. Yet, with the outbreak of World War II, he summarized mainstream Zionist policy saying: "We will assist the British in the war as if there were no White Paper and we must resist the White Paper as if there were no war." Tens of thousands of Palestinian Jews volunteered in the British forces, while settlement and immigration continued - in defiance of the White Paper.
In 1942, Ben-Gurion was instrumental in the drawing up of the Biltmore Program - a new agenda for the Zionist movement, which demanded mass Jewish immigration and, for the first time, called publicly for the formation of a Jewish state in Palestine. Adoption of the program constituted a major change in the Zionist movement - the beginning of the ascendancy of Ben-Gurion's activist line, and rejection of "gradualism" championed by Chaim Weizmann (president of the World Zionist Organization), who for over two decades had guided Zionist endeavors and served as the senior spokesman for mainstream Zionism.
When a post-war change of government in Great Britain failed to bring about repeal of the White Paper, even after the tragedy of the Holocaust had become known, confrontation with Britain became unavoidable. In 1946, Ben-Gurion took over the defense portfolio of the Jewish Agency Executive and led the struggle against the British - defying the British blockade against large-scale Jewish immigration, intensifying settlement activity, and eventually challenging British authority.
Deterioration of the situation in Palestine lead Britain to bring the question of Palestine before the United Nations - a step that culminated in the November 29, 1947 UN General Assembly partition plan. On May 14, 1948, when the British Mandate came to an end, Ben-Gurion - as head of a the provisional government - declared the establishment of the State of Israel. Ben-Gurion masterminded and carried out the transition from clandestine force to regular army, dismantling pre-state politicized militias to form a united, apolitical military - the Israel Defense Forces. His military leadership was a rare mixture of pragmatism and vision. His combination of bold, daring and dogged determination, dynamic organization and decisive moves, linked to a deep, almost mystical faith in Israeli youth, played a crucial role in the conduct of the War of Independence and its outcome. Israel emerged from the war victorious, but paid a terrible price: 6,373 killed, almost 1% of the population.