Haapalah / Aliyah Bet

In 1936, Hillel Kook served as a post commander, and later became a member of ETZL General Headquarters.

By mid-1940, the war put a stop to most ITzL אצ"ל activities in Europe, and had severed the connections between Palestine and the group in the United States.
Hillel Kook Peter Bergson and his followers focussed on pressing for a Jewish army to fight in the war against Germany.

In 1941, Yitzhak Ben-Ami, Hillel Kook Peter Bergson, Samuel Merlin, Alex Rafaeli, Arieh Ben-Eliezer, and Eri Jabotinsky replaced the American Friends of a Jewish Palestine AFJP with the Committee for a Jewish Army of Stateless and Palestinian Jews, which lobbied for creation of a Jewish armed force to fight alongside the Allies against the Nazis.
The Committee for a Jewish Army of Stateless and Palestinian Jews employed protest tactics unheard of in the American Jewish community at that time, placing full page advertisements in major daily newspapers, displaying the names of prominent political figures, intellectuals, and Hollywood celebrities who supported the Jewish army cause.
The Bergson Group’s newspaper advertisements, rallies, and lobbying in Washington, combined with behind the scenes efforts by the established Jewish organizations, persuaded the British to establish the Jewish Brigade הבריגדה היהודית, an all-Jewish military unit that was part of the British Army.