The Algiers Agreement of 1975 was signed on March 6, 1975, between Iran and Iraq to settle the territorial disputes over sovereignty of the Arvand Rud, with Algerian President mediating. Saddam Hussein later tore up the treaty on live television in 1980, as Iraq invaded Iran.

The roots of the tensions between Iran and Iraq go back centuries, involving the Arvand Rud (Shatt al‑Arab), ideological differences, relations with global powers, border disputes, rivalry in the Persian Gulf, ethnic minorities, and the Kurdish issue. They resulted in the signing of several treaties over time:

1- The 1639 Treaty between Safavid Iran and the Ottoman Empire, which vaguely defined borders.

2- The 1746 Treaty between Nader Shah and the Ottoman Sultan, repeating the same ambiguities of the 1639 Treaty.

3- The First Treaty of Erzurum, which was signed following the two-year wars of 1821– 1823, confirmed the terms of the 1746 Treaty but failed to put an end to the border disputes.

4- The Second Treaty of Erzurum, signed in 1847 between Iran and the Ottoman Empire with British mediation, stipulated that a joint commission made up of representatives from both sides would be responsible for precisely determining the border lines.

5- The Tehran Protocol (December 21, 1911) and the Constantinople Protocol (1913), which set up a boundary commission made up of representatives from Iran, the Ottomans, Russia, and Britain to demarcate the borders.

6- The 1937 Treaty, based on which Iraq argued that the Second Treaty of Erzurum (1847) and the 1911 and 1913 protocols had already established Ottoman sovereignty over the Arvand Rud (Shatt al‑Arab). In response, Iran declared the Treaty of Erzurum and the said protocols null and void. Under the 1937 Treaty, Iraq finally abandoned its claim to full sovereignty over the Arvand Rud (Shatt al-Arab). Iran and Iraq agreed that their common border would essentially follow the lines set out in the Constantinople Protocol of 1913 and the notes of the 1914 Boundary Commission. However, because the 1937 Treaty focused on technical and legal details, it failed to settle the border disputes definitively, always leaving room for ambiguity and conflicting interpretations.⁠[1]

In 1957, during talks in Karachi, the prime ministers of Iran and Iraq agreed to resolve their border disputes with the help of a Swedish arbitrator. However, following a coup in Iraq, relations between the two countries became strained.⁠[2]

The July 1958 coup in Iraq, which brought Abd al-Karim Qasim to power, shattered the stability and balance in Iran-Iraq relations — a stability that had largely stemmed from the similarity of their ruling regimes (both monarchies). It exposed and, in some cases, intensified hidden tensions, leading to limited border clashes. With the rise of Abd al-Rahman Arif, relations between Iran and Iraq saw a relative improvement, but this situation did not last much longer than the leftist Baathist government’ s rise to power in Baghdad in July 1968.⁠[3]

With the Baath Party coming to power in Iraq, led by President Hassan al-Bakr — who claimed leadership of the Arab world — the issues grew more complex. Iraq asserted that the Arvand Rud belonged to Iraq and that the islands of Greater Tunb, Lesser Tunb, and Abu Musa were part of the Arab world.⁠[4]

Iran-Iraq relations, particularly during the 1970s and 1980s, were influenced by the policies of the superpowers in the region. Iran’ s dependence on the United States during the reign of Muhammad-Reza Pahlavi placed the country in the Western camp, while Iraq drew increasingly closer to the Soviet Union.

In 1972 and 1973, bloody clashes broke out along the Iran-Iraq border. Consequently, in February 1974, Iraq requested that the United Nations Security Council hold an emergency session to address its complaint. After several meetings, the Security Council announced that it would dispatch a special representative of the UN Secretary-General to the region to address the crisis, based on the agreement of both parties. The successful mission of the UN representative led to a ceasefire on March 7, 1974, between Iran and Iraq. The representative’ s findings showed, first, that Iran and Iraq were using different maps with conflicting border lines, which was itself a source of disagreement and conflict; and second, that both countries had deployed excessive military forces along their borders, which provoked tensions. Based on these conclusions, the UN representative was able to secure both sides’ willingness to form a new boundary commission and warned them against provocative actions. Subsequently, Iran and Iraq were able to continue their negotiations in a calmer atmosphere during the autumn of 1974 and early 1975.⁠[5]

The summit of OPEC member states, held in Algiers from March 4 to 6, 1975, provided an opportunity, with the mediation of Algerian President Houari Boumé diè ne, for a meeting between Muhammad-Reza Pahlavi, the Shah of Iran, and Saddam Hussein, Vice President of Iraq. Following their talks, a comprehensive agreement to resolve the disputes between the two countries was announced as follows:

1. Their land borders would be determined based on the Constantinople Protocol of 1913 and the minutes of the 1914 meetings.

2. Their maritime borders would be determined based on the thalweg.

3. In this manner, the two countries would establish mutual security and trust along their shared borders, committing to maintain precise and effective control to prevent any infiltration or intervention of a subversive nature.

4. The above provisions are inseparable components, constituting an overall solution, and the violation of any one of them contradicts the spirit of the Algiers Agreement.⁠[6]

Following this agreement, Iran’ s Foreign Minister Abbas-Ali Khalatbari and Iraq’ s Foreign Minister Sadoun Hammadi, with the participation of Algerian Foreign Minister Abdelaziz Bouteflika, met in Tehran on March 15, 1975. The outcome of this gathering and subsequent meetings in Baghdad and Algiers was the treaty ratified on June 13, 1975, concerning the state border and neighborly relations between Iran and Iraq, along with three appended protocols, which put an end to the two states’ land and maritime border disagreements.⁠[7]

After the Algiers Agreement, relations between the two countries reached their highest level. Iranian Prime Minister Amir-Abbas Hoveyda visited Iraq in April 1975, and a few weeks later, Saddam Hussein, Vice President of Iraq, visited Iran. Both sides expressed satisfaction in implementing the provisions of the Algiers Agreement to settle outstanding disputes between the two countries, preserve religious and historical ties, maintain good neighborly relations, and expand these ties in various fields that served the mutual interests of both nations.⁠[8]

Both superpowers, the United States and the Soviet Union, wanted an end to the Iran-Iraq disputes. The nightmare of a cutoff of Persian Gulf oil exports was one factor that continually encouraged the United States to pursue a policy of dé tente in the Persian Gulf region. On the other hand, reaching an agreement between Iran and Iraq encouraged Baghdad— which was seeking to break out of its political isolation and take on a more active role in the Arab world — to distance itself from the Soviet Union. This provided a strong incentive for the United States to welcome the resolution of the Iran-Iraq disputes. The Soviet Union, for its part, had both extensive military and economic ties with Iraq and good relations with the Shah of Iran. A confrontation between the two countries could have placed the Soviet Union in a difficult position.

Regionally, both countries wished to pursue their ambitious goals. Shah intended to act as the region’ s supreme power and the gendarme of the Persian Gulf, serving as a stabilizing factor. Iraq, meanwhile, believed that resolving its long-standing disputes with Iran would be effective in playing a leadership role in the Arab world.

The occurrence of the Islamic Revolution in Iran (1979) upset the balance of power not only in the Middle East but also in the world. It confronted the great global powers with new and emerging problems and ultimately provoked them into devising plans to eliminate the new Islamic system of Iran. Saddam Hussein, who had received exaggerated and false reports about the weakness and inefficiency of the Islamic Republic of Iran’ s military capabilities, and was aware of Iran’ s equipment limitations, unilaterally canceled the Algiers Agreement of 1975 — which he himself had signed on behalf of Iraq — and invaded Iran.⁠[9]

On September 17, 1980, five days before Iraq’ s official invasion of Iran, Saddam Hussein appeared at an extraordinary session of the Iraqi National Assembly and said: “ I announce before you that we consider the March 6, 1975 Algiers Agreement completely null and void, and the Revolutionary Command Council will make a decision in this regard”. After Iraq attacked Iran, Saddam Hussein tore up the agreement in front of television cameras and announced, “ This agreement belonged to a time when we were weak. Now we are strong, and we no longer need this agreement”.