 Johnson entered the United States Foreign Service in 1935.After serving in Tokyo, Seoul, South Korea, Mukden (now Shenyang, where he was interned at the start of World War II), and Rio de Janeiro, Brazil, he was assigned as Consul and later Consul General at Yokohama, Japan from 1945 to 1949.From 1949 to 1953, he served in various positions in the Department of State's Far East Bureau, mainly concerned with Japan and Korea, rising to be Deputy Assistant Secretary of State with responsibilities for the entire bureau."