Iran–Iraq War

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Lore & Background

The Iran–Iraq War, known in Iran as the First Imposed War, began with an Iraqi invasion in September 1980 and concluded with a United Nations-brokered ceasefire in August 1988. The conflict is the deadliest conventional war between regular armies of developing countries, resulting in approximately 500,000 deaths, excluding those from the related Anfal campaign. The war was characterized by large-scale trench warfare and deliberate attacks on civilians, including Iraqi chemical weapons attacks. The conflict did not alter any permanent borders, and neither side received war reparations. Low-level military conflict continued until Saddam Hussein’s overthrow in 2003. The war’s range extended across the Iran–Iraq border, with initial Iraqi advances into Iranian territory stalling by December 1980. Iran recaptured all its lost territory by June 1982, then launched a five-year offensive into Iraq. In mid-1988, Iraqi counter-offensives created a military stalemate that preceded the ceasefire. The defining characteristics include the Iraqi goal of preventing Iran’s post-revolutionary ideology from spreading to Iraq’s Shia majority, and Iraq’s desire to replace Iran as the dominant Persian Gulf power. The war followed long-standing border disputes, particularly over the Shatt al-Arab river, which Iraq had ceded to Iran in the 1975 Algiers Agreement. Iraq expected a swift victory due to Iran’s post-revolutionary chaos, but the conflict became protracted. Iraq received support from the United States, the United Kingdom, the Soviet Union, France, Italy, Yugoslavia, most Arab countries, and the National Council of Resistance of Iran. Iran was aided by Syria, Libya, North Korea, China, South Yemen, Pakistan, Cuba, Israel, the Kurdistan Democratic Party, and the Patriotic Union of Kurdistan. Iraq also increased support for Arab separatists in Iran. Iran eventually agreed to a ceasefire due to military and economic losses, decreasing morale, intensifying relations with the United States, and limited international action against Iraqi attacks on civilians.

Reader's Guide

The war began when Iraq invaded Iran in September 1980. Iraqi leader Saddam Hussein aimed to prevent Iran's new revolutionary ideology from spreading to Iraq, retake the eastern bank of the Shatt al-Arab river ceded in the 1975 Algiers Agreement, and replace Iran as the dominant Persian Gulf power. Iraq expected a quick victory against post-revolutionary Iran, but their invasion stalled by December 1980. Iran recaptured all its territory by June 1982, then launched a five-year offensive into Iraq. In mid-1988, Iraqi counter-offensives created a military stalemate. The conflict involved trench warfare, deliberate attacks on civilians, and Iraqi chemical attacks. Around 500,000 died (excluding the Anfal campaign). The war ended with a UN-brokered ceasefire in August 1988, no border changes, and no reparations. Both sides suffered financially and continued low-level conflict until Saddam's overthrow in 2003.

Did You Know?

• The war caused around 500,000 deaths, making it the deadliest conventional war ever fought between regular armies of developing countries.
• Iraq's invasion had stalled by December 1980, and Iran recaptured all its territory by June 1982.
• Iraq used chemical weapons against Iranian soldiers and civilians during the conflict.
• The war ended with a UN-brokered ceasefire in August 1988, with no border changes and no reparations.
• Both sides continued low-level military conflict until relations improved after Saddam's overthrow in 2003.

Roots of the Conflict: Territory, Ideology, and Fear

The hostility between Tehran and Baghdad did not emerge from a single flashpoint but from decades of accumulated grievance. In 1937, Iran and Iraq signed a treaty over the Shatt al-Arab river, requiring Iranian ships to pay tolls. In 1969, Iran broke the treaty, arguing it was unfair, and sailed naval forces down the river in a show of force. Tensions lasted until the 1975 Algiers Agreement, when Iraq ceded the eastern bank of the river to Iran. That territorial concession became a persistent sore in Baghdad's memory. After Iran's 1979 revolution, Khomeini called on Iraqis to overthrow the Ba'ath government. Saddam gave a speech in July 1979 praising the revolution and calling for friendship, but Khomeini rejected it by calling for Islamic revolution in Iraq. Saddam was alarmed, seeing Iran's new Islamic administration as an existential threat to the secular Ba'ath government. In April 1980, the Iran-backed Islamic Dawa Party attempted to assassinate Tariq Aziz, forming part of Iraq's casus belli. Iraq responded by executing Muhammad Baqir al-Sadr and his sister. Saddam's primary interest also stemmed from his desire to right the 'wrong' of the Algiers Agreement and achieve hegemony over the Persian Gulf. He saw Iran's weakness due to revolution, sanctions, and isolation, and had invested heavily in Iraq's military since 1975, buying weapons from the Soviet Union and France. By 1980, Iraq possessed 242,000 soldiers, 2,350 tanks, and 340 combat aircraft.

Eight Years of Attrition: From Blitzkrieg to Stalemate

Iraq expected a decisive victory, considering Iran's post-revolutionary chaos, but their invasion had stalled by December 1980. The Iranian military then gained momentum and recaptured all their territory by June 1982. Rather than stopping at the restored border, Tehran launched a full-scale invasion of Iraqi soil, committing to a grinding five-year offensive that never achieved a breakthrough. The conflict devolved into vast trench systems, punctuated by deliberate Iraqi chemical-weapons strikes against Iranian soldiers and civilians. In mid-1988, Iraq launched a series of counter-offensives that created the military stalemate present at the war's end. The cumulative toll was staggering: roughly half a million killed, not counting victims of the separate Anfal campaign, making it the bloodiest conventional war ever fought between the regular armies of developing nations. The war did not create any permanent border changes, and neither country received war reparations afterwards. Both sides suffered financially and continued engaging in low-level military conflict until relations improved following Saddam's overthrow in 2003.

A Web of Foreign Patronage

The conflict quickly drew in a sprawling constellation of external actors. Iraq was aided by the National Council of Resistance of Iran, the United States, the United Kingdom, the Soviet Union, France, Italy, Yugoslavia, and most Arab countries. Iran was aided by the Kurdistan Democratic Party, the Patriotic Union of Kurdistan, Syria, Libya, North Korea, China, South Yemen, Pakistan, Cuba, and Israel. The irony of these alignments was stark: Cold War rivals such as Washington and Moscow simultaneously supplied Baghdad, while Tehran found partners in both the Soviet-aligned and the Western-aligned camps. Iraq also supported Arab separatists in Iran, seeking to fracture the country from within. This patchwork of patronage meant that neither side could claim exclusive international legitimacy, and the war became a proxy theater in which superpower interests, Arab regional rivalry, and Kurdish aspirations all intersected.

The Ceasefire and Its Long Shadow

After years of military and economic losses, decreasing morale, intensifying Iran–U.S. relations, and little international action against Iraqi attacks on Iranian civilians, Iran agreed to a ceasefire with Iraq under United Nations Security Council Resolution 598. The settlement left the pre-war borders intact; neither nation extracted reparations from the other, and both emerged financially scarred. The formal end of hostilities did not, however, end the hostility. They continued engaging in low-level military conflict until relations improved following Saddam's overthrow in 2003.