Dee ihe na-esote paragraf a - Aarnio bụ onye ọrụ afọ ofufo na White Guards na Savonia Front n'oge Agha Obodo Finnish. Ka oge na-aga, o sonyere n'agha nnwere onwe Estonia, agha nnwere onwe Latvia na njem Aunus
n'Ebe Ọwụwa Anyanwụ Karelia. Aarnio si n'ọrụ agha nọ n'ọrụ banye n'òtù ndị ọrụ nchekwa na 1920. Ọ gụsịrị akwụkwọ na Kadettikoulu na 1926 na Sotakorkeakoulu na 1933. Aarnio e buliri ya n'ọkwa onye isi n'afọ 1929 ma jee ozi na ngalaba mmekọrịta mba ofesi nke General Staff.