The development and growth of Jewish self-defense organizations in Palestine reflected the slow but increasing hostility held by Arabs for Zionism’s presence and growth.
In 1909, Bar Giora and Hashomer were established by volunteers to guard against sporadic Arab attacks on newly established Jewish farms and villages. In June 1920, these organizations dissolved into the Haganah, the unofficial Jewish underground self-defense organization, and grew noticeably in budget and manpower after the Arab riots against Jewish persons and property in 1929 and from 1936-39. For the last decade of the Mandate, the Haganah developed special units that assisted in illegal Jewish immigration to Palestine, one being the Palmach, a leadership strike force. Independent of the Haganah’s growth, in 1931, the Irgun, or National Military Organization, grew under the leadership of Revisionist Zionist leader Zeev Jabotinsky, and from 1943 onwards by Menachem Begin. Unlike the Haganah, led by David Ben Gurion as head of the Jewish Agency, the Irgun focused on offensive operations against Arab and British targets, aimed at hastening British departure from Palestine. A smaller, more strident underground Jewish military group formed as the Stern Gang, or Lehi, which was led by Yitzhak Shamir. Both Begin and Shamir would later become Prime Ministers of Israel. During Israel’s Independence War, the Lehi and the Irgun dissolved into the newly established Israel Defense Forces, a citizen’s army, which became Israel’s military backbone. With few exceptions, every Israeli does compulsory military service. Over the state’s duration, many of Israel’s one time highest ranking military personnel became important political and entrepreneurial leaders of the state.