evidence: Among the causes of the war—the ruthless ambition of Saddam Hussein; ongoing disputes over control of the strategic Shatt al-Arab waterway, a shipping lane formed by the confluence of the Tigris and Euphrates Rivers that created the southern borders of both countries; the struggle for dominance in the Persian Gulf region—the overriding issue was a centuries-old dispute regarding sovereignty over oil-rich Khuzestan Province in southwestern Iran. Khuzestan was the ancient home of the empire of Elam, an independent, non-Semitic, non-Indo-European-speaking kingdom whose territory spanned almost all of present-day southwestern Iran. Khuzestan had been attacked and occupied many times by various Arab kingdoms of Mesopotamia, the precursors of modern-day Iraq.