Chaim Weizmann institute was a global success attracting scientists from all over the Diaspora. In 1949 there were 20 researchers, twenty years later there were 400 and 500 students. The Honourable Chaim Weizmann met with United States President Harry Truman and worked to obtain the support of the United States, they discussed emigration, for the establishment of the State of Israel. The President lived at Rehovot, where he regularly received the Prime Minister David Ben-Gurion into his garden. He was denied any actualisation of the political role he had hoped for by the Left. He had to be consoled with the Weizmann
Chaim Weizmann in his autobiography that the failure of the international Zionist movement (between the wars) to encourage all Jews to act decisively and efficiently in great enough numbers to migrate to the Jerusalem area was the real cause for the call for a Partition deal. A deal on Partition was first formally mentioned in 1936 but not finally implemented until 1948. Again, Weizmann blamed the Zionist movement for not being adequate during the best years of the British Mandate. At the outbreak of war in Europe in 1939, Weizmann was appointed as an Honorary adviser to the British Ministry of Supply,