Shatt al-Arab Waterway Dispute: From 1639 to the Iran-Iraq War

The Shatt al-Arab waterway dispute is a border conflict over control of the river formed by the meeting of the Tigris and the Euphrates, which flows into the Persian Gulf. The problem began with the Ottoman-Iranian border treaties and continued between Iraq and Iran after the Ottomans. It seemed to be solved by the 1975 Algiers Agreement, but in 1980 it became one of the causes of the Iran-Iraq War.

Quick Summary

The river is formed by the meeting of the Tigris and the Euphrates and is about 200 km long.
The region came under Ottoman rule from 1534; the border with Iran was drawn by the Treaty of Qasr-e Shirin in 1639.
The document that regulated the waterway most comprehensively was the 1847 Treaty of Erzurum.
After the First World War, the problem continued between Iraq and Iran.
The 1975 Algiers Agreement set the border along the river’s deepest line.
In 1980 Iraq declared that it no longer recognized the agreement and went to war with Iran.

What is the Shatt al-Arab?
Why is the waterway so important?
The waterway in the Ottoman period
The 1847 Treaty of Erzurum and the border commission
After the Ottomans: Iraq and Iran
The 1975 Algiers Agreement
The Iran-Iraq War and after
Frequently asked questions

What Is the Shatt al-Arab?

According to the TDV Encyclopedia of Islam, the word “shatt” literally means “great river” and “fertile land on a riverbank”. The Euphrates and the Tigris meet about 45 km south of Qurna to form this river. The river flows for about 200 km, and its width varies between 400 and 1,200 meters. Finally it empties into the Persian Gulf at its southern end, where the town of Fao stands.

The waterway forms the southern section of the Iraq-Iran border and is suitable for shipping. Basra on the Iraqi side and Abadan and Mohammerah (Khorramshahr) on the Iranian side are the important ports on its banks. The encyclopedia also draws attention to the vast date groves along the river’s banks. In the years when the entry was published, this region supplied much of the world’s demand for dates.

Why Is the Shatt al-Arab Waterway So Important?

For Iraq, this river was the most important gateway to the sea. Iraq’s coastline on the Persian Gulf is very short, and its largest port, Basra, lies on the banks of this river. Iran, by contrast, has a long coastline along the Gulf, but the Abadan refinery and the port of Khorramshahr also depend on the same water. That is why whether the border should run along the middle of the river or along one of its banks was a vital economic question for both countries. With the rising importance of oil, this rivalry became even fiercer.

The Shatt al-Arab in the Ottoman Period

The region came under Ottoman rule in the middle of the sixteenth century. According to the entry “Basra” in the TDV Encyclopedia of Islam, the city passed under Ottoman administration when Suleiman the Magnificent took Baghdad in 1534. In 1538 the ruler of Basra, Rashid ibn Mughamis, sent the keys of the city to the sultan. From the same year, Suleiman’s name began to appear on the coins struck in Basra.

In the Ottoman period Basra was a lively trading city. It lay on the route that ran from the Persian Gulf, by way of the waterway, to the Mediterranean ports. According to the encyclopedia, the Venetian merchant Cesare Federici, who passed through the city in 1563, described Basra as one of the centers of the spice trade with Hormuz. In 1849 the Ottoman administration began work to move the city to the edge of the waterway and improved the Basra shipyard. We discussed the region’s place in this period in our article on the Ottoman state under Suleiman I.

The waterway also became part of the Ottoman-Iranian border. The Treaty of Qasr-e Shirin (Zuhab) of 1639 expanded the area of Ottoman administration and fixed the border with Iran. According to the encyclopedia, the treaties of 1746 and 1823 concerning the region generally preserved the situation established by this treaty. You can find the background of the long struggle in our article on the Ottoman-Iranian wars.

The 1847 Treaty of Erzurum and the Border Commission

The document that dealt with the Shatt al-Arab most comprehensively was the treaty signed in Erzurum in May 1847. According to the TDV Encyclopedia of Islam, the settlement reached there remained in force until the eve of the First World War. The border commission set up by the treaty made a detailed study of the region possible.

Mehmed Hurşid Pasha, a member of the commission, traveled along the border between 1848 and 1852. The pasha later gathered his observations in his work known as the “Seyâhatnâme-i Hudûd” (Travelogue of the Border). The work describes the border running north from the Persian Gulf, together with the tribes and settlements along it. That is why it is still a source consulted today on the region’s geography and people.

Shortly before the war, a new settlement with Britain was sought. According to the encyclopedia, in 1913 the former grand vizier İbrahim Hakkı Pasha and the British Foreign Secretary Sir Edward Grey signed an agreement. Known as the Anglo-Ottoman Convention, this document left the entire waterway, except Mohammerah, under Ottoman sovereignty. Because of the outbreak of the First World War, however, it was never implemented.

After the Ottomans: Iraq and Iran

After the First World War, the kingdom of Faisal, son of Sharif Husayn, was established in Iraq (23 August 1921). The Iraqi government thus gained a say over the waterway. In the same years, the rise of Reza Shah in Iran and the oil of the region increased the interest of the Western powers. Basra, Abadan and Mohammerah became important ports, especially for the transport of oil.

Before long a dispute began between the two countries. According to the encyclopedia, in 1934 Iran appealed to the League of Nations, protesting that the waters surrounding Mohammerah and Abadan remained under Iraqi sovereignty. The two countries signed a new treaty in 1937, but the result was not very different from the 1913 settlement. This treaty ran the border largely along the Iranian bank, bringing it to the middle of the river only off Abadan.

The Saadabad Pact and Turkey’s Role

The timing of the 1937 settlement was no coincidence. According to the TDV Encyclopedia of Islam, talks had been under way since 1934 on a regional cooperation pact between Turkey, Iran, Iraq and Afghanistan. The encyclopedia states that Iraq’s Shatt al-Arab problem and Iran’s claim to Bahrain were overcome during these negotiations. The four countries then signed the Saadabad Pact in Tehran on 8 July 1937. According to the encyclopedia, Turkey’s contribution to resolving the disputes among the member countries was considerable.

Iran never accepted this arrangement, and in 1969 it declared that it did not recognize the 1937 treaty. It then began to send its own ships through the waterway under the protection of warships. The tension grew as it combined with the two countries’ other disputes in the region. Solving the problem required a new agreement.

The 1975 Algiers Agreement

The two countries signed a new agreement in Algiers in March 1975. This agreement fixed the border along the thalweg, the deepest line of the river along which ships can pass. In return, Iran stopped supporting the Kurdish rebellion in northern Iraq. According to the TDV Encyclopedia of Islam, the agreement apparently settled the dispute, and neighborly relations remained good until the Iranian Islamic Revolution of 1979.

In Iraq, however, many circles saw this settlement as a concession. After the revolution, the balance in the region changed rapidly. The video below, which summarizes the subject for exams, also describes the war that followed the agreement.

The Iran-Iraq War and After

According to the encyclopedia, Saddam Hussein, who took complete control of power in Iraq in 1979, declared that he did not recognize the Algiers Agreement. Then, on 22 September 1980, he declared war on Iran. During the eight-year war, the connection of the waterway, which Iran had closed, with the outside world was completely cut off.

The banks of the Shatt al-Arab became one of the fiercest fronts of the war. Iraqi forces captured Khorramshahr in the first months of the war, but Iran retook the city in 1982. Iran, for its part, occupied the Fao Peninsula at the mouth of the waterway in 1986; Iraq retook it in 1988.

The war cost hundreds of thousands of lives on both sides. In 1988 a ceasefire was reached under United Nations Resolution 598. But the question of sovereignty over the waterway was not definitively resolved.

The TDV Encyclopedia of Islam, in its entry published in 2010, states that the question of sovereignty in the region had still not been resolved. According to the encyclopedia, the solution seemed to depend on how relations between Iran, the United States and Iraq would develop after the American occupation of Iraq.

Frequently Asked Questions

Between which countries is the Shatt al-Arab dispute?

The dispute began in the Ottoman period between the Ottoman state and Iran. After the First World War it continued between Iraq and Iran.

Where is the Shatt al-Arab?

It is in southern Iraq and stretches from the meeting point of the Tigris and the Euphrates to the Persian Gulf. The river forms the southern section of the Iraq-Iran border.

What is the thalweg principle?

The thalweg is the deepest line of a river along which ships can pass. The 1975 Algiers Agreement fixed the border between the two countries along this line.

Which treaty regulated the Shatt al-Arab most comprehensively?

In the Ottoman period, the most comprehensive arrangement was the Treaty of Erzurum signed in 1847. The order it established lasted until the eve of the First World War.

Conclusion

The Shatt al-Arab waterway dispute is a long conflict that began with the Ottoman-Iranian border treaties and continued between Iraq and Iran. The treaties of Qasr-e Shirin and Erzurum preserved order in the Ottoman period. After the Ottomans, the treaties of 1937 and 1975 failed to solve the problem, and in 1980 the dispute turned into war. Because of oil transport and its ports, the waterway retains its strategic importance today.