Iranian Revolutionary Guard members arrive for a ceremony celebrating the 40th anniversary of the Islamic Revolution, at the Azadi, or Freedom, Square, in Tehran, Iran, Monday, Feb. 11, 2019. On Feb. 11, 1979. Iran's military stood down after days of street battles, allowing the revolutionaries to sweep across the country, and the government of Shah Mohammad Reza Pahlavi resigned. (AP Photo/Vahid Salemi)