In 1942, he joined the Jewish Brigade as a doctor, joining the Haganah in 1947. From 1948 to 1950, he commanded the Medical Corps of the Israel Defense Forces (IDF), and became Director General of the Ministry of Health after leaving the IDF. He fulfilled this position until 1953, when he moved on to become the director of the Tel HaShomer Hospital (today Chaim Sheba Medical Center, named in his honor).[1]