Wanderlust World Wanderlust World The Iran–Iraq War erupted on September 22, 1980, when Saddam Hussein's Iraq invaded Iran. It became the 20th century's longest conventional war, claiming ~500,000–1 million lives. Causes were a toxic mix of geopolitics, ideology, and resources:
The strategic river (formed by Tigris/Euphrates) is Iraq's only Persian Gulf access. The 1937 Treaty gave Iraq control; the 1975 Algiers Agreement (under Iranian pressure) shifted the thalweg (mid-channel) border to Iran. Saddam abrogated the 1975 treaty in 1980, demanding full sovereignty.
Iran's 1979 Islamic Revolution (Khomeini) threatened to export Shi'a revolution to Iraq's Shi'a majority (60%) ruled by Sunni Ba'athists. Saddam feared internal uprising; Khomeini called for Saddam's overthrow. Mutual existential dread.
Iraq coveted Iran's oil-rich Khuzestan province (Arab-majority, bordering Iraq). Saddam hoped for a quick seizure, Arab uprising, and regime collapse in Tehran.
US lost Iran as ally; saw Iraq as bulwark. USSR armed both. Gulf states (Kuwait, Saudi) funded Iraq, fearing Iranian revolution. Global powers prolonged the war.
Saddam's miscalculation: he believed Iran was weak post-revolution (purged military, hostage crisis). Instead, Iranian "human wave" resilience and revolutionary fervor stalled then reversed Iraq.
The war ended in August 1988 with UNSCR 598, a stalemate, devastated economies, and chemical weapons use—leaving borders unchanged but the region permanently scarred.