Given the existential military threats constantly confronting them, Israelis have always placed a high priority on military intelligence, and from the start of Jewish settlement in Palestine, the Zionists relied on organized intelligence gathering and assessment. The intelligence service of the Hagana (SHAI) initially concentrated on detecting threats to Yishuv communities posed by local bands of Arabs, but it also developed expertise about military and political affairs in the broader Arab world. During World War II, its personnel undertook intelligence and espionage activities in pro-Axis Arab countries in support of the British war effort. At the end of the war, SHAI became actively engaged in Aliya Bet, the illegal immigration of Jews to Palestine. By the spring of 1947, SHAI was preparing for the end of the British mandate by gathering detailed information about the political attitudes of local Arab villages and the military capabilities of the neighboring Arab countries that were massing troops on the borders of Palestine.
Today, intelligence functions are performed by a variety of agencies, including the Israel Defense Forces (under the director of military intelligence), Shin Bet (Shabak)/General Security Services, the political research department of the Foreign Ministry, and the Institute for Intelligence and Special Duties (Mossad). Despite bureaucratic divisions of labor and budgetary constraints, intelligence and assessment remains a vital element of Israel's national security doctrine.
Historical Dictionary of Israel. Bernard Reich David H. Goldberg. Edited by Jon Woronoff..