 As a youth, Banai was a member of Betar, the Revisionist Zionist youth movement and was a founding member of the Irgun in Poland and leader of the Eastern Poland branch of the party.He graduated from the state Gymnasium high school in 1938 and studied law for one year at Vilnius University (1939–1940).In 1941, following the Soviet invasion and shortly before the German invasion of Lithuania, Banai obtained a Sugihara visa and made his way to Israel via Turkey with other members of the Betar.