Shatt al-Arab

The Shatt al-Arab is a major river in the Middle East.

It forms at the confluence of the Tigris and Euphrates rivers. This meeting point is located in the town of al-Qurnah. This town is in the Basra Governorate of southern Iraq. The river flows south until it reaches the Persian Gulf. In this southern section, the river serves as the border between Iraq and Iran.

People in Iran call the river the Arvand Rud. In Iraq, it is known as the Dijla al-Awara. The river is a vital waterway for shipping and regional geography.

Geologically, the river is a relatively recent formation. Originally, the Tigris and Euphrates emptied into the Persian Gulf through a different channel. This channel was located further to the west. The river receives a major tributary called the Karun from the Iranian side. The Karun River carries large amounts of silt into the Shatt al-Arab. Silt is fine sand or mud that settles on the riverbed. This buildup makes the water shallow. To keep the river navigable for big ships, workers must perform continuous dredging. Dredging involves removing the silt from the bottom of the waterway.

Historically, the Shatt al-Arab was home to a massive natural resource. The region once contained the largest date palm forest on Earth. In the mid-1970s, there were between 17 and 18 million date palms. This represented about one-fifth of the 90 million palm trees in the world. However, this forest suffered a massive decline. By 2002, more than 14 million palms had been destroyed. This loss was caused by war, salt, and pests. Only about 3 to 4 million trees remained by 2002. Many of these surviving trees were in poor health.

Control of the river has been a source of conflict for centuries. During the Ottoman-Safavid era, empires fought for its territory. In the 16th century, the Safavids held much of what is now Iraq. They later lost these lands to the Ottomans following the Peace of Amasya in 1555. The Safavids regained control under Shah Abbas I in the early 17th century. However, the Treaty of Zuhab in 1639 eventually ceded the river to the Ottomans. Later, the Treaty of Kerden in 1746 restored those same boundaries. For a long time, no one could agree on a fixed southern border.

In the 20th century, new treaties attempted to define the boundary. In 1937, Iraq and Iran signed a treaty to settle their dispute. This treaty used the thalweg principle to set the border. The thalweg is the line of the deepest point in the river channel. Most of the river was under Iraqi control under this agreement. However, Iran felt this was unfair because most ships using the river were Iranian. In 1969, Iran decided to cancel the 1937 treaty. This led to high tensions between the two nations.

These tensions eventually led to the Iran-Iraq War from 1980 to 1988. The Shatt al-Arab was a primary stage for military battles. The waterway is Iraq's only outlet to the Persian Gulf. This makes it a critical target for controlling shipping lanes. During the conflict, Iranian attacks affected Iraq's ability to use the sea. In 1986, the Iranian capture of the Al-Faw peninsula halted much of Iraq's shipping. Iraq eventually recaptured Al-Faw in April 1988. After the war, both nations agreed to return to the 1975 Algiers Accord. This agreement used the thalweg as the official border.

The river has also been central to more recent history. During the 2003 invasion of Iraq, coalition forces targeted the waterway. Capturing the river was important for delivering humanitarian aid. It also helped stop naval blockades against Iraq. The United Kingdom was tasked by the United Nations to patrol the area. They monitored the river mouth until 2007 to prevent the transport of munitions. Eventually, the UK trained Iraqi naval units to guard the waters. Today, the Shatt al-Arab remains a vital and complex part of the region.