Persian Gulf

THE COUNTRIES BOUNDING the Persian Gulf include OMAN, UNITED ARAB EMIRATES, QATAR (a peninsula off the SAUDI ARABIA coast), BAHRAIN (an island), Saudi Arabia, KUWAIT, IRAQ, and in the north, IRAN. The Persian Gulf is an arm of the ARABIAN SEA extending some 600 mi (970 km) from east to west. It covers an area of approximately 89,000 square mi (230,000 square km) and the greatest depth is 335 ft (102 m). It is connected to the Arabian Sea in the east by the Strait of Hormuz. Its southern coastal area is characterized by low desert plains. The western coast continues as desert plains with a coastal escarpment that leads into a major river delta known as the Shatt al-Arab. The northern coast is more rugged but equally desert. The ancient Greeks named the gulf as “Persian” and so it has appeared in sources from antiquity and is in common use until today. Some Arab states and authors sponsor a modern revision to the “Arab Gulf.”

Persian Gulf

The Persian Gulf has acted as a route for trade since the earliest millennia of human civilization. From 4000 B.C.E. onward, increasing complex trading relationships are supported by archaeological evidence. Trading centers such as Dilham (most likely modern Bahrain) and Madgan (Oman) linked Mesopotamia to the Indus Valley in South Asia. As the dynasties of history grew greater, the more elaborate the trade links. Intervening cities and ports flourished as suppliers and middlemen along this flow of metals, wood, spices, incense, and finished goods. The Persian Gulf proved to be perfect for this gradual growth of trade and enabling technologies. The simplest boats could move down these feeding rivers to the salty shores of the gulf and sea and make their way along coastlines to their partners in trade and commerce.

The domestication of camels led to the expansion of land routes of commerce that enhanced the Persian Gulf trade. Shipbuilding technologies improved and the discovery of the monsoons for seasonal travel to and from India modified routes and trade links. A Persian Gulf coast culture based upon cities of commerce developed and prospered.

The settled people of the Persian Gulf coast differed from the nomadic peoples of the interior of the Arabian Peninsula and the lands along the northern coast of the gulf. The nomads were children of the deserts, and the coastal peoples were dependent upon the sea. One moved across endless deserts to points of water that gave life to their flocks. The other settled on the shores of the endless waters to capture the largess that made their livelihood. If the deserts could not feed their flocks, the nomadic tribes pushed into the settled towns of agriculture and trade.

Cycles of tribal incursion onto the coastal settlements blended Arab culture with that from Mesopotamia and the lands of INDIA, continuing to build a unique Persian Gulf character. Also, these settlements and the tribes that plied the Persian Gulf began to take on an increasingly Arab flavor because of the consistent out migration from the Arab interior. Some Arab tribes from the rocky wastes and scattered oases of the peninsula came to the coasts and adopted the less mobile life of the settlement. Other tribesmen, masters of the sand, became masters of the sea. They took up sailing and began to build the legend of Arab traders and pirates.

In 325 B.C.E., Alexander the Great sent fleets of ships from India to explore the shores and islands of the Persian Gulf. Greek influence was not able to take permanent hold; by 250 B.C.E. the Parthians had brought the gulf under predominantly Persian control for the first time. This control of the Persian Gulf from a northern empire would last until the coming of ISLAM. Islam spread to the gulf during the life of the Prophet Muhammad and soon reached to all peoples on its shores. The prosperity of the Persian Gulf continued as in 750 C.E. Baghdad became the seat of the caliph and the main center of Islamic civilization and power.

Oman was positioned geographically to take advantage of sea routes in the Persian Gulf and to the RED SEA. The lands around the mouth of the Persian Gulf became the stronghold of those seeking to challenge the powers that controlled the Persian Gulf trade from along the Tigris and Euphrates. Thus began a dance of influence in the Persian Gulf as powers in Mesopotamia vied with those in Muscat. This foretold the long history of conflict between those in the Persian Gulf against outside powers who sought to control this strategic body of water because of the wealth it could command.

By the year 1000, Persian Gulf merchants were traveling regularly to Southeast Asia and beyond to CHINA. Their trading efforts were instrumental in spreading Islam, first to India and then to INDONESIA and MALAYSIA. The tribes of the interior remained culturally distinct from the gulf coastal peoples even under Islam. Empires based in Persian and Iraq depended on customs duties from the East-West trade in the Gulf. Those Arabs along the coasts always had to deal with these external factors. This reality led to political compromises and some cultural concessions. Those in the interior often remained more conservative and traditional. The coastal cities and accompanying wealth of trade passed through the hands of many Islamic rulers over the years be they from Mesopotamia, Persia, or Arabia.


European influence in the Persian Gulf dawned with the Portuguese invasion of Oman in 1502. Lasting for only a century, it heralded the coming contentions of colonial powers in the Persian Gulf. Britain gradually took lead as it established protectorates of the Persian Gulf emirates in the 19th century. With the discovery and exploitation of the vast oil potential of the Persian Gulf in the 20th century, the interests of the industrialized world were inextricably tied to these ancient waters of political and economic power. Britain relinquished its role as protector of Persian Gulf commerce to the UNITED STATES soon after World War II.

The United States played a limited part until Iraq invaded Iran in 1980 and the ensuing war threatened the safe passage of oil tankers out of the Persian Gulf. As the land conflict between Iraq and Iran became a stalemate, both sides increasingly moved their attacks into the Persian Gulf. In March 1984, Iraq initiated sustained naval operations in its self-declared maritime exclusion zone that extended from the mouth of the Shatt al Arab to Iran's port of Bushehr. Since the beginning of its invasion of Iran, Iraq had attacked Iranian oil infrastructure as well as neutral tankers and ships trading with Iran.

Iraq expanded the “tanker war” in 1984 by using its French-supplied combat aircraft armed with sophisticated guided missiles. Unprotected neutral merchant ships became favorite targets, and with the very capable Western war technologies, attacks moved farther and farther south. Seventy-one merchant ships were attacked in 1984 alone, compared with 48 in the first three years of the war. Repeated Iraqi attacks on Iran's main oil-exporting terminal at Khark Island failed to stop oil exports but added to the mounting petroleum releases into the Persian Gulf. Iran retaliated by attacking first a Kuwaiti oil tanker near Bahrain and then a Saudi tanker in Saudi waters, making it clear that if Iraq continued to interfere with Iran's shipping, no gulf state would be safe. The entire Persian Gulf was embroiled in the war and awash with the flotsam and jetsam of a focused battle against oil production and export.

Saudi Arabia shot down an Iranian Phantom jet over Saudi territorial waters in 1984, but there was no concerted effort to stop the attacks on shipping. Iraq increased its air raids on tankers that were serving Iran and Iranian oil-exporting facilities in 1986 and 1987. They even began attacking vessels that belonged to the conservative Arab states of the Persian Gulf. Iran responded by escalating its attacks on shipping serving Arab ports in the Gulf. Kuwait became a focus of Iran's attacks. The Kuwaiti government sought protection from the international community in the fall of 1986. The Soviet Union responded first, agreeing to charter several Soviet tankers to Kuwait in early 1987. Washington, which has been approached first by Kuwait and which had postponed its decision, eventually followed Moscow's lead.

On May 17, 1987, Iraqi aircraft launched a missile attack on the USS Stark, killing 37 crew members and crippling the ship. Baghdad issued official apologizes and the U.S. chose to blame Iran for escalating the war and launched a full-scale naval campaign to escort Kuwaiti tankers that were “reflagged” as American vessels and manned by American crews. Iranian small boat attacks and mine-laying operations caused damage to U.S. protected shipping. The U.S. navy retaliated by destroying Iranian offshore oil platforms.

The U.S. naval forces skirmished with Iranian forces and limited their ability to interdict Iraqi supplies and equipment arriving through ports in Kuwait. The USS Vincennes, a missile cruiser, mistook an Iranian commercial airliner as a combatant and shot it down, killing 290 civilians. The Persian Gulf had become a crowded theater of operations with at least ten Western navies and eight regional navies patrolling the area. Merchant ships continued to be damaged and the shipyards along the Arabian coast were operating at full capacity effecting repairs.

The Western nations generally favored Iraq in the conflict, providing military intelligence and selling large amounts of military arms. Both sides attacked civilian targets with missiles and aircraft, increasing the level of casualties and destruction. Iraq used chemical warfare against Iranian military forces. The war ground to a bloody stalemate and both sides agreed to a UN-sponsored cease-fire in 1988.

In 1990, Iraq chose Kuwait as a target for invasion and annexation. Iraq made several spurious claims about Kuwait regarding oil and finances. Rhetoric about illegally pumping oil from under their border, violating production quotas to drive down prices, and not forgiving previous debts were all proffered as complaints against Kuwait. Other Arab states were assisting with mediation when Iraq invaded on August 2, 1990. A U.S. lead military coalition flooded to the Persian Gulf lodging in Saudi Arabia. In 1991 the UNsponsored military coalition defeated the Iraqi army and liberated Kuwait on February 28. U.S.-led coalition forces enforced continuing UN sanctions against Iraq by military attacks and maritime interdiction for a decade.

In 2003, U.S. and British forces invaded Iraq from Kuwait. U.S.-led coalition naval forces continue to operate to ensure the free flow of commerce and security along the shipping lanes in the gulf. The Iraqi navy is operating once again in the Persian Gulf. The United States and other Western powers have shown that they will act against any new instability in the gulf that endangers their national interests.


In 2002, the Persian Gulf countries (Bahrain, Iran, Iraq, Kuwait, Qatar, Saudi Arabia, and the United Arab Emirates) produced about 25 percent of the world's oil. These countries hold almost 65 percent of the world's proven crude oil reserves. The Persian Gulf region also has some 36 percent of total proven world gas reserves. Another significant factor to world industrial interests is that the Persian Gulf countries maintained about 32 percent of the world total oil production capacity. Most strikingly, the Persian Gulf countries normally maintain around 90 percent of the world's excess oil production capacity. Excess production capacity is important in the event of oil supply disruption in other major oil-producing regions or unexpected depletion of stocks.

With the advent of oil exploration, boundary and territory disputes abounded in the gulf. Most have been resolved and the trend is favorable, as all parties look to increased revenues that only peaceful resolution can bring. The flow of oil from the Persian Gulf continues to be primarily by tanker. In 2002, some 88 percent of oil exported from the Persian Gulf transited by tanker through the Strait of Hormuz. Almost 40 percent of all the oil produced for export and trade in the world passes through this CHOKE POINT. JAPAN receives over 75 percent of its crude oil from the Persian Gulf.


The primary factor in pollution of the Persian Gulf is the massive extraction and transport of oil and associated petroleum products. There is a continuous discharge of petroleum effluents from offshore wellheads, underwater pipelines, loading terminals, and runoff from onshore facilities. Estimates of amounts are difficult to gather, but enforceable standards and controls are limited or nonexistent in most national jurisdictions.

The movement of 40 percent of the world's total oil trade through these waters creates shipping-associated discharges of marine diesel fuel, waste, and, of most concern, millions of gallons of contaminated ballast water. The oil sludge, released by the aggregate of tankers traversing the Persian Gulf, is estimated to be around 8 million metric tons per year. The sea bed along the primary routes to the regional oil terminals is often covered with oil sludge. No enforceable international requirements exist to address this daily pollution by oil tankers.

The circulation parameters of the waters in the Persian Gulf along with a high rate of water evaporation as opposed to its fresh water supply add to pollution management challenges. The coastal zone, with its intertidal mudflats and near-shore islands, is important for breeding sea birds and other migrating species. The extensive coral reefs and coastal mangrove forests are especially susceptible to damage and destruction caused by petroleum pollution. The long-term effects on commercial fishing stocks have yet to be determined.