After the Soviet occupation of Lithuania in June 1940, Alantas fled to Germany. His wife and son remained in Lithuania and were deported to Siberia during the June deportation in 1941. In Germany, he was invited to head the Commission of Culture of the Lithuanian Activist Front, a movement of Lithuanian exiles who sought to liberate Lithuania with Nazi German support. Alantas belonged to the radical right wing of the LAF and supported establishment of the . Despite being offered by to head the Commission of Culture in the Ministry of Education in the Provisional Government of Lithuania, his appointment was blocked by the Party of Lithuanian Nationalists and he was appointed as the head of Vilnius Drama Theatre instead. During three years of work, Alantas wrote three plays, two of which were staged. In 1944, Alantas fled to Germany from the approaching Soviet army and became a displaced person in the aftermath of World War II. In 1949, Alantas moved to Detroit, United States, where he worked as a low-wage labourer in a Ford Motors automobile factory until retirement in 1968. He knew French and German, but struggled with English. He dedicated the rest of his life to literary work and published several novels, short stories, and a poetry collection. He was chairman of the in 1967–1971, and was offered jobs editing Lithuanian periodicals but he refused.