What Is the “Thalweg Principle”

The Shatt al Arab (Canal of the Arab, henceforth Shatt) is a 120-mile tidal river that begins at the confluence of the freshwater Tigris and Euphrates rivers in southern Iraq and ends at the head of the Persian Gulf. The dredged, approximately nine-foot deep Shatt is navigable for oceangoing vessels moving up it as far as Basra, Iraq’s chief port.

Map depicting location of the Shatt al Arab at the head of the Persian Gulf.

A view of the Shatt al Arab

The Shatt, in the southern part of its course, forms the renowned boundary between Iraq and Iran. For centuries the Shatt represented the furthest extent of Iraq’s and Iran’s predecessor states, the Sunni Muslim Ottoman Empire and Shiite Muslim Persia, respectively. As such, it has been a flashpoint for hostilities between the two states.

In the discipline of boundary conflicts, preventive diplomacy, and border treaties, a boundary has a specific meaning: it is the line separating two states as defined on paper or marking on the ground.* The International Boundary Research Unit at the University of Durham in the United Kingdom helpfully lists 309 international land boundaries, of which the Iran-Iraq boundary at the Shatt is one.** A border is the area surrounding a boundary. A frontier is the area where two states meet in interests and penetration, while not necessarily with an agreed territorial limit for their aspirations.

For Iraq, the Shatt represents its only true outlet to the Persian Gulf. Iran, by contrast, has a long coast line along the Persian Gulf. Nevertheless, Iran built its great Abadan oil refinery on an island in the Shatt.

Boundary disputes between Iraq and Iran at the Shatt have raged intermittently for thousands of years and a full description is beyond the scope of this essay.* In 1937, for example, the “Boundary Treaty between the Kingdom of Irak and the Empire of Iran” marked the first major agreement between the newly established states of Iraq and Iran. The Treaty expressly sought the definitive settlement of “the question of the frontier between the two states,” and 1) gave Iraq total control of the Shatt, leaving Iran with control only of the approaches to Abadan and Khorrmashar (its chief ports on the Shatt), and 2) forbade Iran to develop new port facilities in the delta.

Following the 1958 coup-etat in Iraq, Iran sought to redraw the Shatt boundary using the thalweg principle (more on this below). In 1975, Iraq and Iran met during the Organization of Petroleum Exporting Countries (OPEC) in Algiers to sign the so-called Algiers Accord, which recognized the line running down the middle of the bottom of the murky Shatt, in the mud, as the official border between Iraq and Iran.

This line, called the thalweg (a German word compounded from “thal”, valley, and “weg”, way), joins the lowest points along the entire length of a streambed or valley. The thalweg principle is the principle of determining national boundaries at the thalweg of a river separating two states.

Saddam Hussein became president of Iraq in 1979. In September 1980 he invaded Iran with the support of Kuwait and Saudi Arabia, ostensibly to retake full control of the Shatt, according to the 1937 Treaty (see above) and also, if possible, to annex Iran’s oil-rich Khuzestan province. What started as a boundary dispute became the bloody Iran-Iraq War, sometimes called the First Persian Gulf War, which lasted eight years (1980-1988) (see http://www.semp.us/biots/biot_150.html). The end of the war left the talweg boundary between Iraq and Iran unchanged.

Only three short years after the conclusion of the Iran-Iraq War in 1988, Saddam Hussein, in the lead-up to the 1991 Persian Gulf War (sometimes called the Second Persian Gulf War), once again recognized the 1975 Algiers Accord (thalweg principle) to appease Iranians before he undertook his invasion of Kuwait to whom he incidentally owed billions of dollars for the Iran-Iraq War. The Shatt, you may recall, was also the site in the Third Persian Gulf War (the one we’re in now) of the brief standoff between the United Kingdom and Iran because eight British crew members and their three vessels were 1,000 meters on the Iranian side of the thalweg.

Editor’s Note: Boundary disputes are reliable sources of conflict, and often escalate to war (e.g., the Iran-Iraq War). Wars and other diffuse happenings that spread across time and space (e.g., famines, epidemics, and droughts—the so-called “FEDs”) are usually separated from the traditional disaster research agenda even though “[i]n popular parlance, and even more so in the more technical/professional literature, these have frequently been labeled “disasters.”*** U.S. disaster researchers focus on earthquakes, hurricanes, floods, chemical plant explosions, and terrorist attacks, among other acute happenings because these happenings are part of their immediate American experience. Even in the United Kingdom, the main groups concerned with the FEDs are not researchers, but international relief groups.

During the past 50 years, disaster research has provided much valuable insight about human behavior during acute collective stress situations. By extending its scope to include the study of the FEDs and other prolonged collective stress situations, disaster research could help us understand how to prevent, mitigate, prepare for, respond to, and recover from FEDs whose effects no longer stay put on the other side of the world.

Comments are welcomed. Please send them to moleary@semp.us.

Sources:

*For additional reading, see:

1. “Boundary Conflicts and Preventive Diplomacy” by Kjell-Ake Nordquist at: http://wwics.si.edu/subsites/ccpdc/pubs/zart/ch2.htm;

2. “An Analysis of Iran-Iraq Bilateral Border Treaties” by Joseph J. Cusimano at: www.macam.ac.il;

3. R.N. Schofield: Evolution of the Shatt Al-Arab Boundary Dispute (Menas studies in continuity & change in the Middle East and North Africa), 1986. No longer in print, but available as an (expensive) used book through online sellers; and

4. K.H. Kaikobad: The Shatt-Al-Arab Boundary Question: A Legal Reappraisal (Oxford Monographs on International Law) 1988. In print for $185.

* *”The World's 309 International Land Boundaries: http://www-ibru.dur.ac.uk/docs/landlist.html.

***EL Quarantelli: What Is a Disaster? Routledge, London, 1998, pp. 260-261.