During the Arab Revolt of 1936-1939, Danin was the leader of a spy network for the Haganah in the district of Samaria. In 1940, he formed the Arab section of the SHAI and remained there until 1948. He was instrumental in the formation of the "Syrian Platoon" of the Palmach in 1940-41, whose goal was to infiltrate Syria and Lebanon who were under Franch Vichy rule.