Since the 1979 revolution in Iran, the country has been under constant US unilateral sanctions. The first U.S. sanctions against Iran were formalized in November 1979, and during the hostage crisis, many sanctions were leveled against the Iranian government. By 1987 the import of Iranian goods into the United States had been banned. In 1995, President of the United States Bill Clinton issued Executive Order 12957, banning U.S. investment in Iran's energy sector, followed a few weeks later by Executive Order 12959 eliminating all trade and investment and virtually all interaction between the United States and Iran.