Unander re-entered the Swedish Army in 1906 and was promoted to Captain in Västerbotten Regiment in 1907. He served in the 1st Life Grenadier Regiment in 1911 and from October 1912 to May 1913 as military attaché in Constantinople, where he took part in the Battle of Lule Burgas and the First Battle of Çatalca during the First Balkan War. Unander served as a special attaché in London from 1917 to 1918 and he was promoted to Major in Norrbotten Regiment the same year. He was acting diplomatic agent and consul general in Egypt from 1919 to 1922 and served in the South Scanian Infantry Regiment ("Södra skånska infanteriregementet", I 7) in 1922. Unander last assignment was as Swedish consul in Zagreb from 1926 to 1929.