The 1948 Women's Armed Services Integration Act established defined roles for women in the peacetime armed forces of the United States. Previously, they only had been allowed to serve as nurses in peacetime; a wider variety of roles only open to them in time of war. However, with the start of the Korean War in June 1950, the Department of Defense began to investigate ways to increase recruitment and retention of women in all services. Internal inquiries from defense agencies such as the National Security Resources Board and external pressure from politicians such as Senator Margaret Chase Smith added to the sense of urgency in defining a more comprehensive position for women in the military.