Weizmann was notable both as a scientist and as a central diplomatic leader of the Zionist movement. He held a post as chemical adviser to the British Ministry of Supply throughout the war, but most of his time and energy went to furthering the Zionist cause. Weizmann had two preoccupations in this regard: first, he wished to have a Jewish Brigade established to fight the Germans. An interview with CHURCHILL in September 1941 appeared to have settled this matter successfully, but the Jewish Commandos were not actually formed until 1944. Secondly, Weizmann wanted to settle the question of Palestine. He had been partly responsible for the Balfour Declaration and so spoke from a long experience of diplomacy. He visited the United States in 1940 and 1941, meeting and organizing Zionists all over the country. He met ROOSEVELT in February 1940. He spent almost a year in the USA from 1942 to 1943 during which time he lobbied State Department officials and politicians on behalf of the Jewish cause. At the same time however he was being challenged from within his own organization by BEN-GURION who objected to his autocratic leadership: and he was already quite an old man. In October 1943 Weizmann met CHURCHILL and ATTLEE who claimed to be committed to partition. In November 1944 Churchill again offered Weizmann assurances. However on 5 November Lord Moyne was assassinated by Zionist extremists which caused a backlash in Britain. Despite Weizmann’s pleas to have faith in Britain, the Zionist Congress decided to have Ben-Gurion as their leader. Weizmann became Israel’s first President in 1948.