Peter H. Bergson was born Hillel Kook in Lithuania in 1915. Bergson was a nephew of Ashkenazi chief rabbi Abraham Isaac Hacohen Kook. At the age of 10 immigrated to Eretz Israel with his family. In 1929, he joined the Haganah and when the Irgun (IZL) was founded, he left the Haganah and joined the new organization.
Graduated in Judaic Studies at the Hebrew University of Jerusalem and was part of the Sohba (Comradeship) - a group of students whom later played key roles in the Irgun, including David Raziel, Avraham Stern and others.
At the end of 1937, Bergson was sent to Poland and engaged in organizing illegal immigration. When World War II broke out, he went to the United States together with several other commanders (including Aryeh Ben Eliezer and Alexander Raphaeli). At first they promoted the establishment of Jewish armed units within the allied armed forces to take part in the war effort against Nazi Germany. When information came through about the mass extermination of Jews, the group set up the Committee for the Rescue of European Jewry. In 1940, he accompanied Vladimir (Ze'ev) Jabotinsky to the United States as a representative of the IZL. After Jabotinsky died in August 1940, Bergson remained in the U.S. to continue his activities.
Bergson's primary assignment in the United States was to mobilize support for the IZL and for the creation of Jewish military units, and, later to gather support for the creation of a Jewish state in Palestine. Bergson set out to accomplish these tasks by creating a series of interlocking organizations, including the Committee for a Jewish Army of Stateless and Palestinian Jews, the American League for a Free Palestine, the Emergency Committee to Save the Jewish People of Europe, and the Hebrew Committee for National Liberation. Supporters of these organizations included Harry Truman, Dorothy Parker, Herbert Hoover, Will Rogers, Jr., Labor leader William Green, U.S. Solicitor General Fowler Harper, and U.S. Interior Secretary Harold Ickes.
The network of organizations issued a strong challenge to the Jewish establishment in the United States by working outside the normally conservative and secret diplomatic channels used by the leaders of such organizations as the American Jewish Committee and the American Jewish Congress. Bergson used direct — and often bombastic — appeals to the American public and to members of Congress to demand the creation of a Jewish army (between 1940 and 1942) and to rescue Jews from Nazi terror by any means (between 1942 and 1944).
While it is difficult to assess the success of Bergson's activities, they resulted in a greater public awareness of the Holocaust, and helped create an atmosphere conducive to changes in American rescue policy. Thus, at the least, Bergson's activities contributed to the creation of the War Refugee Board and the Oswego free port in 1944.
When the Revolt was proclaimed (1944), Bergson, together with several comrades, established the Hebrew Committee for National Liberation. The Committee appealed to the American public and its elected representatives, and won considerable support for the Irgun's activities in Eretz Israel.
When Israel was established, Bergson returned home and reverted to using his Hebrew name. He was elected to the First Knesset on behalf of the Herut movement and served from 1949 to 1951. Disillusioned with his political experience, he left Israel in 1951 with his wife Betty and daughter Astra, and emigrated to the United States. In 1968, four years after his wife's death, he returned to Israel with his daughters Astra and Rebecca. He remarried in 1975 and lived near Tel Aviv until his death in 2001.