Reza Shah refused, claiming this would adversely impact his development projects. Following Germany's invasion of the USSR in June 1941, Britain and the Soviet Union became allies. Both turned their attention to Iran. Britain and the USSR saw the newly opened Trans-Iranian Railroad as an attractive transport route from the Persian Gulf to the Soviet region. In August 1941, because of refusing to expel the German nationals, Britain and the USSR invaded Iran, arrested Reza Shah and sent him into exile, and took control of Iran's communications and coveted railroad. In 1942 the United States, an ally of Britain and the USSR during the war, sent a military force to Iran to help maintain and operate sections of the railroad.
