Iran-Iraq War (1980): Invasion · 474

About 500,000-1 million people died, scholarly range, the majority Iranian in many estimates, with Iraqi losses also enormous. Iraq used chemical weapons against Iranian forces and, in 1988, against Kurdish civilians at Halabja. The UN Security Council's Resolution 598 (1987) framed a ceasefire that both sides accepted in 1988, effective 20 August.

Neither capital got the political victory it had promised. Saddam Hussein's Iraq emerged militarised and indebted -- a prelude to the 1990 Kuwait invasion. Iran's "Sacred Defense" became a founding myth of the Islamic Republic. English-language memory is thin beside Vietnam or 1991; for the Gulf, this was the longer, bloodier war.

A border war that became a war of societies 1980-88 fused a river-border dispute, two authoritarian projects, and great-power tilt -- without a 1945-style settlement. Saddam Hussein read the 1979 Iranian Revolution as weakness. The 1975 Algiers Agreement on the Shatt was torn up. Iraqi forces took Khorramshahr and failed to take a knockout; Iranian resistance and mobilisation surprised Baghdad.