Iran is a southwest Asian country of mountains and deserts. Eastern Iran is dominated by a high plateau, with large salt flats and vast sand deserts. The plateau is surrounded by even higher mountains, including the Zagros to the west and the Elburz to the north. Farming and settlement are largely concentrated in the narrow plains or valleys in the west or north, where there is more rainfall. Iran's huge oil reserves lie in the southwest, along the Persian Gulf.

Shah Mohammad Reza Pahlavi, who came to power in 1941, perpetuated a pattern of autocratic rule extending back to Cyrus the Great, whose Persian Empire reached its zenith in the sixth century B.C. Aided by the U.S., the shah initiated social and economic reforms financed by petroleum exports. His opponents reviled Westernization for tainting Iran's Islamic purity and cultural identity. Revolution broke out in 1978. The shah fled, and Ayatollah Khomeini imposed a fundamentalist theocracy, under which an estimated 70,000 critics were executed. The official state religion is the Shiite branch of Islam, practiced by most Iranians.

War with Iraq from 1980 to 1988 cost a million Iranian lives and devastated the economy. Iran confronts political and social transformation as some promote liberal ideas, while others hold fast to established Islamic traditions. An estimated seven million Iranians have access to the Internet, which has been used to circumvent government censorship. In December 2003 a massive earthquake struck the southeastern city of Bam, killing more than 30,000 people.