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Policy Analysis

PolicyWatch 879

Incident in the Shatt al-Arab Waterway: Iran's Border Sensitivities

Simon Henderson

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Policy #879

June 28, 2004


After several days of diplomatic tension between London and Tehran, eight British military personnel who had been captured by Iran's Islamic Revolutionary Guard Corps (IRGC) were released and flown out of Iran on June 24. The men, who served with the coalition forces in Iraq, had been in three boats intercepted in the Shatt al-Arab waterway, the confluence of the Tigris and Euphrates Rivers that forms the border with Iran. (Tehran, which dislikes the Arab name, calls the waterway the Arvand River.) The incident comes after several weeks of minor clashes in the Persian Gulf and at a time when Iran is facing strong international pressure due to concerns about its suspected nuclear weapons program.

The exact circumstances of the capture of the British personnel are not clear. Tehran has claimed that the men were carrying weapons and sophisticated communications equipment, while British officials have stated that they had only their personal weapons and, at the time of their capture, were merely delivering one of the boats to Iraq's new river patrol service in Basra. The men had apparently crossed into the Iranian portion of the Shatt al-Arab unintentionally. By a 1975 treaty, the border between Iran and Iraq lies along the so-called "thalweg line," the midpoint of the deep-water channel. The precise status of this treaty is currently unclear, however, as Saddam Husayn abrogated it when he launched the Iran-Iraq War in 1980.

Historical Grudges

The fact that British forces were involved made the incident especially sensitive for Iran. A 1937 treaty, brokered at a time when imperial Britain still held sway in Iraq, placed the Iraqi-Iranian border at the low-water line on the Iranian side of the waterway, putting Iran at a considerable disadvantage. (The waterway is tidal up to and north of Basra, which is located fifty miles from the Persian Gulf.) Although the 1937 treaty allowed free passage for all shipping, the effect was that ships heading for the Iranian port of Khorramshahr and the oil refinery at Abadan were placed under Iraqi control, forced to carry Iraqi pilots and pay transit fees to the harbor authorities in Basra. Iran resented this display of British dominance.

The 1975 treaty was negotiated between the Shah of Iran and Saddam (at the time Iraq's de facto second-in-command). In return for Tehran halting its support for a Kurdish rebellion in northern Iraq, Saddam conceded the thalweg line as the border.

Taken by itself, last week's incident could be viewed as a case of poor British navigation and opportunistic zeal by the IRGC, whose fast boats patrol the waterway. Yet, such a view would ignore the fact that there had been previous incidents of this sort in the Shatt al-Arab. According to a senior British officer in Basra, Iraqi patrols attempting to navigate the waterway since the fall of Saddam's regime have been shot at by Iranian forces, whichever side of the thalweg line they have been on. In an attempt to defuse this and other border tensions, the British have placed a senior military "liaison officer" (i.e., not a military attach) in Tehran to deal directly with the Iranian Ministry of Defense.

Other Incidents in the Persian Gulf

In another worrisome trend, other portions of the Persian Gulf have witnessed an outbreak of maritime incidents during the first three weeks of June. On June 2, the United Arab Emirates (UAE) detained an Iranian fishing boat for allegedly sailing into UAE territorial waters around the island of Abu Musa. Iran has long claimed the island, which lies in an area where revenues from the local oil field are shared between the two countries. Iran seized Abu Musa, along with the small islands known as the Greater and Lesser Tunbs, in 1971. The Tunbs are located near the main shipping lanes for oil tankers.

Soon after the June 2 incident, the IRGC stopped seven fishing boats from the UAE and detained twenty-two crew members for entering Iranian waters. On June 11, Iran claimed that a Qatari patrol boat had fired on Iranian fishing boats accused of entering Qatari waters. (One of the world's largest reserves of natural gas lies under the maritime boundary between the two countries.) One Iranian was killed and two were injured, and the boats were seized, according to an Iranian report. The Qatari ambassador in Tehran was summoned to the foreign ministry for an explanation and to inform him that the Iranian fisherman had permits. On June 15, the IRGC seized a UAE fishing boat and its five crew members near the island of Sirri, home to an Iranian oil terminal.

These incidents followed a June 5 meeting between foreign ministers of the Gulf Cooperation Council (i.e., Saudi Arabia, Kuwait, Bahrain, Qatar, the UAE, and Oman), at which Gulf leaders expressed regret that contacts with Iran over Abu Musa and the Tunbs had "so far failed to achieve results" (i.e., with regard to returning them to Arab sovereignty). A day later, an Iranian Foreign Ministry statement asserted that the "islands are and will remain an inseparable and eternal part of [Iran]."

In the Iranian parliament, one deputy speculated that the United States was behind the UAE's June 2 seizure of the Iranian fishing boat. Another deputy suggested the action was timed to coincide with international pressure on Iran over its nuclear facilities. Meanwhile, the managing director of one Iranian newspaper argued that Tehran's sovereignty over the islands could be traced back to official British maps of 1836 (for good measure, he added that the Shah of Iran had no right to give up Iranian claims to the island-state of Bahrain in 1970).

All of these controversial maritime actions by Iran appear to be attributable to the IRGC, the military unit that is most loyal to the regime. The IRGC has land, naval, and air components, along with increasing political power. It answers directly to Iranian Supreme Leader Ali Hossein Khamenei, and several dozen former members were recently sworn in as members of parliament. The IRGC has also been active in Iraq, where it trained the main Shi'i militia (the Badr Brigades) and where it continues to send operatives.

Challenge for the United States

British foreign secretary Jack Straw described the quick resolution of the Shatt al-Arab incident as proof that Britain's "policy of engagement with the government of Iran is the best approach." Sometimes dubbed "Ayatollah Straw" by his critics because of his frequent visits to Tehran, Straw was one of the architects of the European Union agreement with Iran aimed at halting its enrichment of uranium. In fact, Tehran's agreement to surrender the British detainees (instead of, as was suggested at first, putting them on trial) can easily be seen as an effort to earn diplomatic points as the crisis of its alleged nuclear ambitions develops. For Washington, Iran's recent actions demonstrate that Tehran is determined to be seen as a major regional power and that it has an interest in the shape of post-occupation Iraq.

Simon Henderson is a London-based associate of The Washington Institute and author of the Institute Policy Paper The New Pillar: Conservative Arab Gulf States and U.S. Strategy (2003).