The June 1941 German invasion of the Soviet Union unleashed a series of events that culminated in the Allied invasion of Iran two months later. In their propaganda, Britain and the Soviet Union publicly justified that invasion as a means of preventing Iran from falling into the German orbit. However, a review of radio broadcasts of the time shows the theme of a German menace was not widely believed in the region. Using BBC Summary of World Broadcasts transcripts from the period, this paper argues that the decision to base their propaganda on a lie also negatively affected relations in the postwar world. In that sense the decision to justify the invasion on the basis of German presence was a propaganda failure for the allies.