The Algiers Treaty of March 6, 1975, signed by Iran’s Shah Mohammad Reza Pahlavi and then vice president of Iraq Saddam Hussein, was intended to solve longstanding border and waterway disputes between the two neighboring countries.
However, with the overthrow of the shah in 1979, which put Iran in the hands of Islamic fundamentalists, the political dynamics changed. By 1980 Iran’s new leaders started to hint that they did not feel obligated by the shah’s earlier commitments, and Iraqi leaders were complaining that Iran still had not returned certain border areas promised under the 1975 treaty.
In September 1980 Iraqi armed forces moved to reclaim those lands, and on September 22 they crossed the border into Iran. The invasion had consequences that Iraqi president Hussein had not expected. In launching the attack on Iran, Hussein thought the war would be brief and would lead to the downfall of Iran’s religious leader, the Ayatollah Khomeini, whom Hussein disliked. Instead, the power of Khomeini and other Islamic revolutionaries increased as Iranians united and rallied to support the war.
Few had expected Iraq to win the war outright. Although Iraq had better technology, more weapons, and a stronger air force, Iran had three times the population and about four times the geographic area of Iraq. Thus the Iran-Iraq War seesawed back and forth for eight grueling years. Some methods of World War I were employed; Iran, for example, often conducted useless infantry attacks, using “human assault waves” made up in part by young, untrained conscripts, as in the Kerbala offensives, which were repulsed by the superior air- and firepower of the Iraqis. Iraq, concerned with the war’s trench warfare and stalemate, had its overtures for a peace agreement undercut when its reputation was tainted by United Nations reports that it had used deadly (and illegal) chemical weapons against Iranian troops in 1984.
Although both Iran and Iraq attacked each other’s oil-tanker shipping in the Persian Gulf, Iran’s attacks on Kuwait’s and other gulf states’ tankers caused the
United States and several Western European nations to station battleships in the gulf to protect those tankers. This in turn led, on July 3, 1988, to the accidental shooting down of an Iranian civil airliner by the U.S. cruiser Vincennes, which killed all 290 crew members and passengers aboard.
As many as 1 million people died in the Iran-Iraq War, approximately 1.7 million were wounded, about 1.5 million were forced to flee as refugees, and major cities were destroyed on both sides. The oil industries of both countries also suffered extensive damage due to the fighting; oil exports, and earnings from those exports, naturally dropped. More important, the large oil reserves of Iran and Iraq represented the potential for significant international economic power, but both nations had together largely wasted $400 billion on the war and along with that the chance to build up their societies.
The effects of the war clearly reached beyond the two combatants. Iran’s need for additional weapons led to a compromising relationship for the administration of U.S. president Ronald Reagan in 1985. In the secret Iran-contra affair, Iran was able to obtain weapons from the United States (the country that Khomeini had called “the great Satan”) in exchange for the release of hostages in Lebanon. At about the same time U.S. aid of all types began to appear in Iraq, whereas the Soviet Union supplied about two-thirds of Iraq’s weapons. The Iran-Iraq War also ended Khomeini’s attempts to spread his fundamentalist Islamic revolution abroad. Although stymied in his ambitions to make Iraq the leading power in the Persian Gulf (and the Arab world), Iraqi president Hussein learned new fighting strategies that he would later use against another neighboring country, Kuwait, which had been his ally during the conflict.
By the time a cease-fire finally arrived on August 20, 1988, the Iran-Iraq War had been the longest and most destructive conflict in the post–World War II era, and none of the basic friction points between Iran and Iraq had been settled. However, in August–September 1990, while Iraq was busy with its invasion of Kuwait, Iraq and Iran quietly restored diplomatic relations, and Iraq agreed to Iranian terms for the settlement of the war: the removal of Iraqi troops from Iranian territory, division of sovereignty over the Shatt al Arab waterway, and an exchange of prisoners of war.