The Shatt al-Arab dispute was a territorial dispute that took place in the Shatt al-Arab region from 1936 until 1975. The Shatt al-Arab was considered an important channel for the oil exports of both Iran and Iraq, and in 1937, Iran and the newly independent Iraq signed a treaty to settle the dispute. In the 1975 Algiers Agreement, Iraq made territorial concessions—including the Shatt al-Arab waterway—in exchange for normalized relations. In return for Iraq agreeing that the frontier on the waterway ran along the entire thalweg, Iran ended its support for the Peshmerga in the Second Iraqi–Kurdish War. The Iraqi government reneged on the Agreement shortly before launching the Iran-Iraq War in 1980, but accepted it once more after the war.[1]