After the war, he resumed the practice of law, also entering politics in the factions led by fellow townsman Nicolae Iorga. He was deputy mayor in 1919–1920 and mayor in 1931–1932 as well as in 1941–1944. In 1940, prior to the area's Soviet occupation, Missir was commander of the Cernăuți rail station. As mayor, he was the last to leave the evacuated Botoșani in March 1944, during the Uman–Botoșani Offensive. He died the following year, prematurely.