The first major threat to the security of the Persian Gulf states followed the outbreak of war between Iran and Iraq in 1980. The war began after a period of deteriorating relations between these two historic rivals, dating from the fall of Mohammad Reza Shah Pahlavi in 1979 and his replacement as Iranian leader by Ayatollah Sayyid Ruhollah Musavi Khomeini. Full-scale warfare erupted in September 1980 as Iraqi military units swept across the Shatt al Arab waterway--which forms the confluence of the Tigris and Euphrates rivers--into the province of Khuzestan, Iran's richest oil-producing area. Iraqi president Saddam Husayn hoped to overthrow Khomeini, who had been overtly attempting to spread his Islamist (also seen as fundamentalist) revolution into Iraq, where the minority regime of Sunni (see Glossary) Muslims ruled over a majority population of Shia Muslims.

By November 1980, the Iraqi offensive had lost its momentum. Rejecting an Iraqi offer to negotiate, Khomeini launched a series of counteroffensives in 1982, in 1983, and in 1984 that resulted in the recapture of the Iranian cities of Khorramshahr and Abadan. The destruction of huge oil facilities caused both belligerents sharp declines in oil revenues. Iraq was able to obtain substantial financial aid from Saudi Arabia and other gulf states. In early 1986, an Iranian offensive across the Shatt al Arab resulted in the fall of the Iraqi oil-loading port of Faw and the occupation of much of the Faw Peninsula almost to the Kuwait border. But the Iranians could not break out of the peninsula to threaten Basra, and their last great offensive, which began in December 1986, was ultimately repelled with heavy losses. In the spring of 1988, the freshly equipped Iraqi ground and air forces succeeded in retaking the Faw Peninsula and, through a succession of frontal assaults, continued into Iran. Iranian battlefield losses, combined with Iraqi air and missile attacks on Iranian cities, forced Khomeini to accept a ceasefire , which took effect in August 1988.

Initially, the fighting between Iran and Iraq only peripherallyaffected the Persian Gulf states. In May 1981, Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the UAE banded together in the GCC to protect their interests and, if necessary, to defend themselves (see Collective Security under the Gulf Cooperation Council , this ch.). In 1984 Iran reacted to Iraqi air attacks on Iran's main oil terminal on the island of Khark by attacking ships destined for ports in gulf countries that assisted Iraq's war effort. Iranian links with a coup attempt in Bahrain in 1981, Shia terrorist activity in Kuwait, and Iranianinspired violence in Mecca underscored the conviction of the Arab states of the gulf that Iran was the primary threat to their security.

Iran stepped up the tanker warfare in early 1987 by introducing high-speed small craft armed with Italian Sea Killer missiles. Kuwait had already sought the protection of United States naval escorts through the339 he gulf for reflagged Kuwaiti vessels. Determined to protect the flow of oil, the United States approved and began tanker convoys in May 1987. Eleven Kuwaiti ships--one-half of the Kuwaiti tanker fleet--were placed under the United States flag. Other Kuwaiti tankers sailed under Soviet and British flags. Although United States escorts were involved in a number of clashes with Iranian forces and one tanker was damaged by a mine, Iran generally avoided interfering with Kuwaiti ships sailing under United States protection.

Data as of January 1993