Although Klingberg said that he was not a Zionist, he claimed that he moved to Israel because he was a Jew and because the Soviet Union supported Israel at that time. He was drafted into the Israel Defense Forces, and served in the Medical Corps. In March 1950, he advanced to the rank of Lt. Colonel (Sgan Aluf). He served as Head of the Department of Preventive Medicine and afterward he founded and chaired the Central Research Laboratories for Military Medicine.