Balutis started his diplomat career when he was delegated to represent Lithuanian Americans at the Paris Peace Conference in 1919. The delegation was recalled in December 1919 and Balutis was offered a job dealing with "particularly important matters" at the Ministry of Foreign Affairs in Kaunas. Balutis was involved in negotiating essentially every major international agreement in the difficult post-war years. He was involved in negotiating the Latvia–Lithuania border and the Soviet–Lithuanian Peace Treaty of July 1920. As situation shifted quickly in the Polish–Soviet War, Balutis was a member of the Lithuanian delegation that concluded the Suwałki Agreement of October 1920 with Poland. After Poland staged the Żeligowski's Mutiny and captured Vilnius Region, Balutis represented Lithuania at the mediation efforts by the League of Nations. When Lithuania staged the Klaipėda Revolt in January 1923 and captured Klaipėda Region, Balutis and Vaclovas Sidzikauskas negotiated the Klaipėda Convention which was concluded in May 1924.