Iran–Iraq War

War between Iran and Iraq (1980–88), claimed by the former to have begun with the Iraqi offensive on 21 September 1980, and by the latter with the Iranian shelling of border posts on 4 September 1980. Occasioned by a boundary dispute over the Shatt-al-Arab waterway, it fundamentally arose because of Saddam Hussein's fear of a weakening of his absolute power base in Iraq by Iran's encouragement of the Shiite majority in Iraq to rise against the Sunni government. An estimated 1 million people died in the war.

The war's course was marked by offensive and counter-offensive, interspersed with extended periods of stalemate. Chemical weapons were used, cities and the important oil installations of the area were the target for bombing raids and rocket attacks, and international shipping came under fire in the Gulf (including in 1987 the US frigate Stark, which was attacked by the Iraqi airforce). Among Arab states, Iran was supported by Libya and Syria, the remainder supporting Iraq. Iran also benefited from secret US arms shipments, the disclosure of which in 1986 led to considerable scandal in the USA, Irangate. The intervention of the USA 1987, ostensibly to keep the sea lanes open, but seen by Iran as support for Iraq, heightened, rather than reduced, tension in the Gulf, and United Nations attempts to obtain a ceasefire failed. The war ended in August 1988 after ceasefire talks in Geneva.