In customary and treaty-based international law of armed conflict, a ceasefire refers to a halt in firing and a temporary suspension of hostile and military operations for the purpose of arranging peace or addressing other concerns.

A ceasefire is an essential element of an armistice and generally involves the following steps: both parties issue ceasefire orders to their forces; each side may adjust its defensive positions behind the ceasefire lines but cannot deploy new forces or equipment; the parties maintain communication to avoid clashes between their forces and to discuss minor local adjustments; temporary lines of separation are agreed upon and a demilitarized zone may be designated; and military observers accountable to the UN Security Council oversee the ceasefire’ s implementation.

In several twentieth-century armed conflicts, including the France-Vietnam War (July 20, 1954), the Peru-Ecuador conflict (February 5, 1981), the Falklands War (June 14, 1982), and three Arab-Israeli wars (1956, 1967, 1973), hostilities ended with a ceasefire but without a subsequent peace treaty. The Iran-Iraq War (1980– 1988) likewise ended with a ceasefire and no new peace agreement.

The Baathist regime officially invaded the Islamic Republic of Iran by land, air, and sea on September 22, 1980. One day after the war began, Habib Chatti, then Secretary-General of the Organization of Islamic Cooperation (OIC), sent separate messages to Imam Khomeini (ra) and Saddam Hussein, explicitly calling for an immediate ceasefire; a call endorsed the same day by the nine member states of the European Community in a joint statement. The Baathist Iraqi government, however, announced on the second day of the war that it had seized areas roughly sixteen kilometers inside Iranian territory, including the cities of Mehran and Qasr-e Shirin, and had Abadan and Khorramshahr under siege. It announced that any ceasefire depends on accepting three conditions: recognition of Iraqi sovereignty over the border areas, recognition of and respect for Iraq’ s sovereignty and legitimate rights over the Arvand waterway, and the return of three Persian Gulf islands to their Arab owners. That same day, UN Secretary-General Kurt Waldheim wrote to the presidents of Iran and Iraq calling for a ceasefire and negotiations for a peaceful resolution of the dispute.

On September 28, 1980, Saddam Hussein declared that Iraq’ s war objectives had been achieved and announced his readiness for a ceasefire. The Security Council convened that day and passed its first resolution — No. 479 — without calling for a ceasefire. Iranian President Abolhassan Bani-Sadr stated that Iran would accept a ceasefire on two conditions: the complete withdrawal of Iraqi forces from occupied areas, and Iraq’ s commitment to non-interference in Iran’ s internal affairs. The ceasefire proposals put forward by international organizations did not incorporate these demands, and Iran rejected them — including the OIC resolution at Taif on January 28, 1981, and the OIC peace committee plan in early 1981.

The breaking of the Abadan siege and the recapture of Bostan in the fall of 1981 led Saddam in early 1982 to speak of demarcating international borders on the basis of the 1975 Algiers Agreement and readiness for an unconditional ceasefire. After Operation Beit al-Muqaddas and the liberation of Khorramshahr on May 24, 1982, the UN Secretary-General emphasized the need for a ceasefire between the two countries and an end to the war.

On May 31, 1982, members of the (Persian) Gulf Cooperation Council pressured Iraq to withdraw fully from the occupied territories. As a result, on June 10, Saddam ordered all his forces to observe a unilateral ceasefire, and on June 11, he issued a withdrawal order. On June 22, Imam Khomeini (ra) stated that Iraq’ s withdrawal was only one of Iran’ s conditions for ending the war. He also demanded war reparations, the removal of Saddam Hussein, and the right of passage for Iranian forces through Iraqi territory to fight Israel. Iran’ s permanent representative to the UN stated on July 2 that Iraqi forces had only withdrawn from indefensible positions in the plains to heights that were part of Iranian territory, where they had repositioned.

When Operation Ramazan began and Iranian forces entered Iraqi territory, regional and international pressure on Iran to accept a ceasefire intensified sharply. On July 14, 1982, the Security Council responded to Iraq’ s request to condemn Iran’ s military attack and take appropriate action. Therefore, it issued a statement on July 15 — the third day of the operation — calling the situation between Iran and Iraq dangerous and urging all possible means to end the war.

The failure of Operation Ramazan broke Iran’ s chain of battlefield victories and produced a ground war stalemate that lasted through early 1984.

After Operation Moslim ibn Aqil in Sumar and the establishment of Iranian control over the heights overlooking the Iraqi city of Mandali, the Security Council passed Resolution 522, which called for an immediate ceasefire and cessation of military operations, withdrawal of forces to the international borders, and the dispatch of UN observers to examine, verify, and monitor the ceasefire. The UN General Assembly also passed a resolution on October 22, 1982, calling for an immediate ceasefire and withdrawal to international borders.

When Operation Valfajr 4 began on October 19, 1983, the Security Council convened at Iraq’ s request and passed Resolution 540 in which, for the first time, an impartial examination of the causes of the war was raised as a desirable objective. Iraq welcomed the resolution, but the Islamic Republic responded that the Council was persisting in its unbalanced approach and that Iran had no choice but to reject it.

As the Tanker War in the Persian Gulf intensified in 1984, the Security Council convened on June 2, 1984, and passed Resolution 552, which, without mentioning Iraqi attacks, characterized attacks on ships as a threat to regional stability, security, and international peace. Iran dismissed the resolution as invalid and contrary to UN Charter principles, citing its failure to condemn Iraq as the aggressor and hold it responsible for war reparations. As the Tanker War continued, fighting in the Persian Gulf escalated, and the bombing and shelling of civilian centers increased. Following these attacks, with UN Secretary-General mediation, the parties implemented a ceasefire in what became known as the “ June 1984 Agreement” (June 13, 1984). Despite the temporary ceasefire in the War of the Cities, attacks on shipping in the Persian Gulf continued at full intensity.

In April 1985, the UN Secretary-General proposed a three-month ceasefire plan. However, Iran accused the Security Council of unfair and non-neutral conduct and conveyed to the Secretary-General its conditions: condemnation of the aggressor and payment of reparations. With this plan going nowhere, Iraq increased political and military pressure on Iran. It intensified the War of the Cities and launched missile attacks on oil terminals, all in an attempt to force Iran to accept a ceasefire. Iran carried out several operations in response, and after the successful Operation Valfajr 8 in February 1986, non-permanent Security Council members drafted a resolution identifying Iraq as the aggressor. However, the five permanent members objected to the draft and instead called for an immediate ceasefire. Iran again rejected it, stating that the first step toward a just resolution was the explicit condemnation of Iraq as the aggressor. In early 1986, Imam Khomeini (ra) emphasized the continuation of the military operation at Al-Faw until Saddam’ s fall and the elimination of the Baath Party. The Iraqi army continued attacking Iranian oil tankers and terminals in the Persian Gulf and, in April, destroyed 31 of the 36 oil storage tanks on Kharg Island.

On August 3, 1986, Saddam Hussein wrote a letter to the Iranian people proposing a ceasefire, which Iran left unanswered.

Pressure on Iran to accept a ceasefire and end the war intensified in late 1986. The Security Council passed Resolution 588 on October 8, calling for an immediate ceasefire. Iraq welcomed the resolution, but Iran dismissed it as lacking the essential elements of a just solution and as a futile attempt to help Iraq.

The Security Council’ s permanent members prepared a binding resolution in June 1987 calling for an immediate ceasefire. Resolution 598 was then passed on July 20. Iran again stated its position and rejected it as well. The Security Council and Secretary-General, however, kept pushing to implement the resolution.

Iraq carried out a chemical bombing of the city of Halabja on March 17, 1988, and declared it would use every available weapon to force Iran to accept a ceasefire, adding to the pressure through missile strikes on Tehran. From April to July 1988, Iraq recaptured large areas of its territory previously under Iranian control, including Al-Faw, Shalamcheh, the Majnoon Islands, and Zubaidat. Iranian forces also retreated from areas such as Haj Omran and Halabja. Meanwhile, limited clashes between Iranian and American forces in the Persian Gulf intensified. On July 3, 1988, a US warship fired a missile at an Iranian civilian airliner, and all aboard were martyred. Under these circumstances, Iran accepted Resolution 598 on July 17, 1988.

The effective and official ceasefire on the warfronts came into force at 6:30 AM on August 20, 1988, and the two parties began direct negotiations for the establishment of peace under the supervision of the UN Secretary-General.⁠[1]