From 1980 to 1988, Iran and Iraq fought the longest conventional war of the twentieth century. The tragedies included the slaughter of child soldiers, the use of chemical weapons, the striking of civilian shipping in the Gulf, and the destruction of cities. The Iran-Iraq War offers an unflinching look at a conflict seared into the region's collective memory but little understood in the West. Pierre Razoux shows why this war remains central to understanding Middle Eastern geopolitics, from the deep-rooted distrust between Sunni and Shia Muslims, to Iran's obsession with nuclear power, to the continuing struggles in Iraq. He provides invaluable keys to decipher Iran's behavior and internal struggle today.