Skip to main content

Algiers Agreement (1975)


Agreement between Iran and Iraq to settle border and political disputes.

On 6 March 1975 Iran and Iraq announced in Algeria that they had agreed to recognize the thalweg (middle) of the Shatt al-Arab River as their common border and to resolve other contentious issues. Their riparian border had become a major issue in 1969 when Iran unilaterally abrogated a 1937 treaty that had reaffirmed, with the exception of a thalweg line at the Iranian port of Abadan, an Iran-Ottoman Empire treaty of 1913 establishing the common boundary along the Iranian shore of the Shatt al-Arab. Iran claimed that the 1937 treaty had been signed under British duress and that the principle of thalweg should be applied along the entire course of the river. Iran's action led to a series of border clashes beginning in 1971. Algeria mediated the 1975 agreement, which led to the signing of a bilateral border treaty at Baghdad in June.

Iraq renounced the Algiers Agreement and abrogated the Baghdad Treaty in September 1980 just before launching its invasion of Iran. Iran and Iraq accepted UN Security Council resolution number 598 establishing a cease-fire in 1988, but most of the graduated steps, including those pertaining to their common border, remained unimplemented in the early 2000s. However, even though the Algiers Agreement has not been reinstituted formally, Iran and Iraq have observed a de facto thalweg as their border in the Shatt al-Arab since the fall of 1990.

see also shatt al-arab.


Kaikobad, Kaiyan Homi. The Shatt-al-Arab Boundary Question: A Legal Reappraisal. New York: Oxford University Press; Oxford: Clarendon Press, 1988.

Mia Bloom

Updated by Eric Hooglund

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Algiers Agreement (1975)." Encyclopedia of the Modern Middle East and North Africa. . 14 Feb. 2019 <>.

"Algiers Agreement (1975)." Encyclopedia of the Modern Middle East and North Africa. . (February 14, 2019).

"Algiers Agreement (1975)." Encyclopedia of the Modern Middle East and North Africa. . Retrieved February 14, 2019 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.