The Soviet ultimatum led to a new "people's government" in Soviet-occupied Lithuania which Greimas was sympathetic to. In July 1940, he gave speeches urging Lithuanians to elect leaders who would vote in favor of annexation by the Soviet Union. As his friend Aleksys Churginas advised, in every speech he would mention Stalin and end by clapping for himself. In October, he was discharged into the reserve, and he began teaching French, German, Lithuanian and humanities at schools in Šiauliai. He fell in love with socialist Hania (Ona) Lukauskaitė, who later became an anti-Soviet conspirator with Jonas Noreika, served ten years in a lager in Vorkuta, and was a founder of the Lithuanian Helsinki Group of anti-Soviet dissidents. Greimas became an avid reader of Marx. In March 1941, Greimas's friend, Vladas Pauža, a boy scout and fellow teacher, enlisted him in the Lithuanian Activist Front. This underground network was preparing for a Nazi German invasion as the opportunity to restore Lithuania's independence and drive out all of Lithuania's Jews. On 14 June 1941, the Soviets detained his parents, arresting his father and sending him to Krasnoyarsk Krai, where he died in 1942. His mother was deported to Altai Krai. Meanwhile, during these traumatic deportations, Greimas had been mobilized as an army officer to write up the property of detained Lithuanians. Greimas became an anti-Communist but retained a lifelong affinity with Marxist, leftist and liberal ideas.