In 1918, during the
Finnish Civil War, Laatikainen returned to Finland as a
jäger lieutenant and took part in the civil war on the side of the
Finnish Whites. He saw action in the
Battle of Kämärä on 27 January 1918 and the
Battle of Viipuri that was fought between 24 and 29 April 1918. He also saw combat in
Lempäälä. He was made a member of the
Order of the Cross of Liberty in 1918. In 1919, Laatikainen married Julia Emilia Grönroos (1888–1967) with whom he had three children. The youngest, Esko Armas Laatikainen (born 1920) would later die during the Continuation War in 1942. His two other children were Marjatta Laatikainen (later Toivakka, born 1925) and Erkki Antero Laatikainen (born 1928), the latter of whom would reach the rank of
lieutenant general in the Finnish Army. Following the end of the civil war, he continued his military career commanding first a company and then a battalion, being promoted to the rank of
captain in 1919. In 1921, he was promoted to the rank of
major and made the commander of the
Reserve Officer School. In 1927, he was made the commander of the
Officer Cadet School, which was responsible for training war-time company commanders. While in these roles, he was made a knight of the
Order of the White Rose of Finland in 1923 and promoted to a
colonel in 1928. From 1933 onward, he served as a regimental (1933–37), military province (1937–1938) and finally divisional (1938–1939) commander. He was made a
major general in 1938. During this time, Laatikainen also served as a member of the
Hamina city tax board from 1925 to 1926 and as a member of the
Huopalahti municipal council from 1928 to 1930. He also continued to be active in the Jäger affairs, serving on the board of
Jääkäriliitto (lit. Jäger Union), the Jäger heritage society from 1926 to 1930. He received the
Danish Order of the Dannebrog Knight 1st Class in 1933 and the
Estonian
Order of the Cross of the Eagle 3rd class in 1936. == During the Winter War and the Interim Peace ==