Iran–Iraq War

The Iran–Iraq War began with Iraq's invasion of Iran on 22 September 1980 and ended with a United Nations-brokered ceasefire in August 1988. Fought largely along the border between the two countries, it became a war of trenches, mass infantry assaults, missile strikes on cities and chemical weapons. It killed perhaps half a million people, yet left the borders unchanged.

The two states had long quarrelled over their border, above all the Shatt al-Arab waterway, where Iraq had ceded the eastern bank to Iran under the Algiers Agreement of 1975. The Iranian Revolution of 1979 brought Ayatollah Ruhollah Khomeini to power and created a Shia Islamic republic. Iraq's president, Saddam Hussein, whose Ba'athist government was controlled by Sunni Muslims, feared that Iran would export its revolution and rally Iraq's Shia majority against him. He also saw an opportunity: Iran's armed forces had been weakened by revolutionary purges, and he hoped to retake the whole waterway and make Iraq the leading power in the Gulf.

On 22 September 1980 Iraqi aircraft struck Iranian airfields, and the next day Iraqi troops crossed the border on a wide front. Their main thrust was into the oil-rich province of Khuzestan, where Iraq hoped, in vain, that the Arab population would rise in its support. After weeks of street fighting, the Iraqis captured the port of Khorramshahr, but the advance was slow and poorly led and had stalled by December. Iran mobilised its army, the Revolutionary Guards and the new Basij volunteer militia.

In 1981 and 1982 Iran struck back. In May 1982 it recaptured Khorramshahr, taking some 19,000 Iraqi prisoners, and by June it had regained nearly all its lost territory. Iran then decided to carry the war into Iraq, and over the next five years it launched more than 70 offensives, several aimed at the southern city of Basra and its links to Baghdad, often using massed infantry attacks. Iraq dug in, doubled the size of its army and turned increasingly to chemical weapons. The front became a costly stalemate.

Iraq received weapons, money and loans from many states, including the Soviet Union, France, the United States and most Arab governments, while Iran was supported by Syria, Libya and others. Unable to win on the ground, Iraq attacked Iranian shipping and oil exports, and Iran retaliated against tankers in the Gulf, drawing in Western navies. Both sides fired missiles at each other's cities in the "war of the cities". In March 1988, after Iranian forces and Kurdish fighters took the Iraqi Kurdish town of Halabja, Iraq attacked it with poison gas, killing thousands of civilians. It was part of a wider campaign of repression against Iraq's Kurds, culminating in the Anfal campaign, which the historian Efraim Karsh says had assumed genocidal proportions by 1988.

In 1988 Iraq regained the al-Faw peninsula and other ground in a series of offensives. In April a clash with the United States Navy cost Iran several warships, and on 3 July the American warship USS Vincennes shot down an Iranian airliner, killing 290 people. Facing further chemical attacks and economic exhaustion, Iran accepted Security Council Resolution 598 on 20 July 1988. Khomeini said he did so with great reluctance. The ceasefire took effect in August.

Estimates of the dead vary widely. Britannica suggests perhaps 500,000 killed in all, with Iran suffering the greater losses; Iran's own figures are around 200,000 to 220,000 dead, and Iraqi deaths are estimated at 105,000 to 200,000. Neither side gained territory or reparations. Iraq emerged with a large army but heavy debts, much of it owed to Gulf neighbours, and its accusations that Kuwait was stealing its oil helped lead to the invasion of Kuwait in 1990 and the Gulf War. In 1991 the UN Secretary-General reported that Iraq's attack had been unjustified.

Our 1985 map shows Iran and Iraq in the middle of the war, and the 1994 map shows the same border after it.