Iran’s nuclear program is believed to have steadily progressed, despite sharply increased concerns over its intentions and sanctions over its lack of transparency.

Iran is a predominantly Shiite Muslim state but contains sizeable ethnic and religious minorities that influence Iran’s foreign and regional policy.

Since cutting ties in 1979, U.S.-Iran dialogue has been sparse and largely fruitless.

Iran’s Supreme Leader remains the regime’s ultimate authority but controversy surrounding the country’s June 12 presidential election has raised new questions about the role and power of the head of …