Self-Defense Force was formed during a meeting of the Ahdut Avodah party. It was designed to take the place of the Ha-Shomer Ha-Tzair movement, and was dedicated to havlagah, or self-defense. The original idea had been proposed by Israel Shochat eight years earlier. With the onset of the British Mandate the Zionist leaders had thought there would not be a need for a self-defense organization. The Arab attacks earlier that year proved them wrong. Eliyahu Golomb was its first commander.