1975 Algiers Agreement

The 1975 Algiers Agreement, also known as the Algiers Accord and the Algiers Declaration, was signed between Iran and Iraq to settle any outstanding territorial disputes along the Iran–Iraq border. Mediated by Algeria, it served as the basis for additional bilateral treaties signed on 13 June 1975 and 26 December 1975. The territorial disputes in question concerned Iraq's Shatt al-Arab and Iran's Khuzestan Province, and Iraq had wished to negotiate to end Iran's support for the then-ongoing Iraqi Kurdish rebellion after suffering a military defeat in the 1974–1975 Shatt al-Arab conflict. On 17 September 1980, shortly after the Iranian Revolution, the Iraqi government abrogated the treaty in light of another series of cross-border clashes between the two countries. On 22 September 1980, the treaty was completely voided with the Iraqi invasion of Iran, which triggered the eight-year-long Iran–Iraq War.

Since the 2003 invasion of Iraq, the detailed boundary delimitation of the treaty has remained de jure in force and binding under international law (per UNSC Resolution 619), though there is occasional friction between the two countries over the state of their border in the context of smuggling and the Iraqi conflict.