In 1941 the Soviet Union invaded northern Iran and remained there as an occupying force through 1946. During this time, the Soviets not only pursued their military interests, but worked to strengthen socialist movements in Iran. Notably, Soviet Azerbaijani officials sought to influence Iranian Azerbaijani politics and culture, promoting Soviet sensibilities about nationalities among their southern brethren. Shortly after the Soviet occupation, a contingent of Soviet Azerbaijani artists took up residence in Tabriz, took over the theater, and started supplying movie houses with Soviet films. In this paper I will investigate the role of nationality and ethnicity in both Iranian and Soviet Azerbaijani identity formation by considering the failures and successes of the Soviet Azerbaijani project of defining Azerbaijan during the 1940s. This project contributed to the short-lived Azerbaijan People’s Government (1945-1946), but ultimately did not create common identities across the two Azerbaijans that, after a century of separation, had developed independently. I will look at the Azerbaijani plays and operas performed during the occupation, notably early-20th century works by artists such as Uzeyir Hajibeyov, which often featured Iranian settings and characters, and the work of the writer Suleyman Rustam, who recounts his leadership of the Soviet artists in Tabriz in a series of memoirs and whose poetic drama Qachaq Nebi is set during the Russian imperial era and takes place partly in northern Iran. I will then look at some of the representation of Iranian Azerbaijan in Soviet films, notably The Other Side of the Aras’s Arabic Script (1945), a short film about the continued use of Arabic script for the Azeri language in Iran, presented in contrast to Soviet Azerbaijan’s alphabet reform from Arabic to Latin and then Cyrillic, and The Other Side of the Aras (1947), a dramatization of the Azerbaijan People’s Government. Using these sources, I will analyze how performance promoted an Azerbaijani national identity that took root in Soviet Azerbaijan, how Soviet Azerbaijani figures attempted to promote this identity in Iran, and how ultimately two Azerbaijan’s, intimately linked but distinct, continued their separate trajectories.