Concurrent with his administration’s efforts to solidify Khomeinist political and cultural hegemony by crushing MEK and university opposition to clerical rule, Khamenei’s first term was also notable for the conduct of the Iran-Iraq War. Despite diverting significant attention to suppressing internal unrest, dealing with the spate of assassinations of multiple prominent IRP officials, and contending with an economic crisis, the government was able to marshal sufficient resources to turn the tide of the war in the early years of Khamenei’s presidency. The fall of Banisadr’s presidency and the emergence of a more uniformly Khomeinist government translated into a greater unity of command over and discipline within the ranks of the IRGC and conventional armed forces. The conventional army and IRGC began to cooperate far more closely than under Banisadr when suspicions abounded about the conventional army’s loyalty to the Islamic Republic. Iran began to use its significant manpower advantages, and the IRGC – newly battle-hardened after a year of combat experience – led the way to a string of Iranian successes.

During the first months of the war, Iraq had taken advantage of the Iranian armed forces’ disarray and conquered more than 4,000 square miles of Iranian territory. Their offensive stalled, however, after Iran’s predominantly Arab population in Khuzestan province responded to the invasion with increased nationalism rather than welcoming Iraq and rebelling against the Islamic Republic, as Saddam Hussein had hoped. Advancing farther into Iran and conquering more cities would therefore require massive numbers of additional troops, which Iraq opted against, deciding to fortify and defend the territory it had taken. Iran began its counteroffensive to retake the territory occupied by Iraqi forces shortly before Khamenei assumed the presidency, notching its first major success in September 1981 when Iranian forces broke the year-long siege of Abadan, home to Iran’s key oil installations. Iran’s advances continued during the early stages of Khamenei’s presidency with a string of small victories, culminating in a major turning point in the war when Iranian – predominantly IRGC – forces recaptured the country’s most important port, Khorramshahr in May 1982. More small victories ensued, and shortly thereafter, Iraq held only 200 square miles of Iranian territory.

With Iran en route to reclaiming its full territorial integrity and the Iraqi armed forces badly demoralized, Saddam Hussein began looking for a face-saving way to end the conflict. On June 6, 1982, Israel invaded southern Lebanon, and Saddam Hussein subsequently ordered Iraqi troops to abandon the Iranian conflict, ostensibly to bolster Syrian and Palestinian Liberation Organization (PLO) forces in their fight against Israel. Hussein called on Iran to stop fighting and redirect its resources toward the war with Israel. However, the clerical leadership, euphoric following its victories, dismissed Hussein’s entreaties. Hussein sought out numerous international interlocutors to broker a peace deal with Iran, but with Khomeini setting the tone, Iran rejected multiple offers and insisted on maximalist terms, including the restoration of the 1975 treaty borders with Iraq, the admission of full guilt for the war, more than $150 billion in reparations, and the removal of Saddam Hussein from power. Faced with these impossible terms, Hussein announced he was continuing with the withdrawal of Iraqi troops from Iran unilaterally to remove any pretext for the continuation of the conflict, repositioning them to form a line of static defense along the border to ward off a potential Iranian counter-invasion.

Hussein had hoped that a decisive victory against Iran would cement his status as the leader of the Arab world, but his failures left Iraq reliant on other Arab states for support and his grip on power shaky. Ayatollah Khomeini had similar visions of grandeur for the Islamic Revolution, which he envisioned as growing into a supranational liberation movement for oppressed Muslims the world over, with himself serving in effect as velayat-e faqih (supreme spiritual guide) for the entire Islamic World. Following the Iranian recapture of Khorramshahr in May 1982, an internal debate occurred within the upper echelons of Iran’s leadership over whether to press the war into Iraqi territory. According to Ayatollah Khomeini’s son, Ahmad, who served as his chief of staff and most trusted advisor, the Imam initially thought it best to end the war after the reconquest of Khorramshahr, as he feared the war would “never end” if an Iranian invasion did not quickly succeed.

Despite their rivalries, Iran’s primary civil leaders, including President Khamenei, Prime Minister Mousavi, and Foreign Minister Velayati, were generally united in a moderate outlook when it came to the question of pressing the war into Iraq, a view they shared with the conventional army. They feared that the military would become overextended and that the human and material costs would be exorbitant, possibly imperiling the stability and future of the Islamic Revolution. However, Khamenei and his more moderate compatriots’ outlook was quickly overshadowed by the prevailing atmosphere of triumphalism after the reconquest of Khorramshahr. Many saw the hand of the divine in the rapid string of Iran’s decisive defeats of Iraq’s better-equipped, most elite forces. More hardline and radical clerics in the majles and on the Supreme Defense Council, headed by majles speaker Akbar Hashemi Rafsanjani, as well as many top military commanders, particularly in the IRGC, felt the time was ripe to take out Saddam Hussein once and for all. Iraq was facing financial difficulties due to its loss of oil exports and growing unrest in the country’s predominantly Shi’a south, which led many Iranian military and political officials to conclude that the Iraqi Shi’a would ally with the Islamic Revolution and Khomeinism in order to be liberated from Saddam Hussein’s secularist Sunni Baathism.

Beyond removing the threat of Saddam Hussein, the more radical elements of Iran’s leadership saw the continuation of the war as the perfect opportunity to kickstart the project of exporting the Islamic Revolution and cleansing the region of Western influence. Iraq was home to some of Shi'a Islam's holiest cities and shrines. Iran’s leadership stoked religious fervor about liberating Karbala to drum up support for continuing the war. More importantly, Saddam’s downfall and extending the dominion of the Islamic Revolution to Iraq was framed as a stepping stone on the path to liberating Jerusalem.

Khomeini’s initial caution over invading Iraq evaporated almost immediately as he bought into the messianism of his most radical backers. Having repelled the Iraqi invasion and gained the upper hand against, but not completely quashed, MEK-led domestic unrest, Khomeini sought to marshal the rising tide of militarism and revolutionary fervor to facilitate the final consolidation of the Islamic Revolutionary regime and cement clerical control. Khomeini biographer Baqer Moin said, “Khomeini was also persuaded that the revolution would not be allowed to survive if it remained within Iranian borders. He began to see himself as the acclaimed leader and liberator of oppressed Muslims from both the Eastern bloc and from Western powers represented by Zionism.”

On June 21, 1982, the debate over whether to continue the war was settled, as Khomeini issued a statement calling for Saddam Hussein’s overthrow. Khomeini declared his intention to establish an Islamic government allied with Iran in Iraq, which he hoped would spur a domino effect among the smaller Gulf nations. Iran set about creating the Supreme Council of the Islamic Revolution in Iraq (SCIRI) that year. This proxy political party later developed a militant armed wing intended to lay the groundwork for establishing a Khomeinist Islamic Revolutionary government in Iraq. Iran would replicate this model in Lebanon, where it initially backed Amal and then was pivotal in founding the more militant, explicitly Khomeinist Hezbollah, the Gulf, and beyond. To export its revolutionary ideology, Iran focused on indoctrinating Shi’a communities through propaganda and funding social services in tandem with the IRGC, which funded, equipped, and trained militant elements and subversive activities.

President Ali Khamenei and the other civil leaders who advised against carrying on the war in Iraq had no choice but to quickly abandon their misgivings once Khomeini’s decision was made. The near civil war at home was raging on, spurring the escalation of external militarism. In the prevailing climate, it was virtually unthinkable to advocate moderation. The public statements of senior political and military officials became increasingly bellicose, including Khamenei’s, who explicitly backed the notion of extending Khomeini’s guardianship over Iraq and beyond. In one such speech, Khamenei declared, “The future government of Iraq should be an Islamic and a popular one. The policy of velayat-e faqih will be Iraq’s future policy, and the leader of the Islamic nation is Imam Khomeini. … Government and state officials are limited to international borders, but the Imam is not limited by geographical frontiers.”

Khomeini’s decision to carry the war into Iraq was ill-fated. The Islamic Republic’s seemingly miraculous successes in reconquering its territory led to hubris among Khomeini and his advisors, who overestimated both Iran’s military capabilities and the universalist ideological appeal of Khomeinism. Just as Iran’s Arabs did not ally with Saddam Hussein following the Iraqi invasion, neither did the Iraqi Shi’a rally to support the Iranian invasion. Despite Iran’s advantages in terms of the size of its forces and the revolutionary zeal of its IRGC and basij partisans, it proved unable to overwhelm Iraq’s technical superiority and defensive advantages. The war became a fruitless war of attrition with no off-ramp in sight.

Iran’s decision to invade Iraq brought it renewed regional and international opprobrium, curtailing Iran’s military procurement capabilities. The Gulf monarchies, which in 1981 formed a collective defense organization, the Gulf Cooperation Council (GCC), over fears of Iran’s revolutionary export, rallied to support Saddam Hussein, fearing the Iranian invasion represented an escalation toward spreading the revolution through full-scale warfare rather than political meddling and acts of subversion that Iran had been doing. The Soviet Union, which had been neutral at the onset of the war and sold arms to both sides, tilted toward Iraq after Tehran’s crackdown on the pro-Soviet Tudeh party in 1983, becoming Saddam Hussein’s largest arms provider with sales totaling $11.5 billion between 1984-1987. France became Iraq’s largest Western benefactor, which Iran’s leadership took as evidence of an “imperialist front” designed to crush the Islamic Revolution. Iran’s mistrust of the West was further reinforced during this period by the U.S. pressuring its allies not to sell arms and to curtail its business investment in Iran while at the same time providing diplomatic cover for Saddam Hussein’s war crimes, which included targeting Iranian civilians, energy infrastructure, and the use of chemical weapons.

Despite Iran’s lack of progress in overthrowing Saddam Hussein, conquering and holding Iraqi territory, and liberating Shi’a holy sites in Iraq, Ayatollah Khomeini pursued his crusade, framing it as a religious duty, regardless of the human and material costs borne by the Islamic Republic. Because Iran could not procure advanced weaponry or materiel compatible with its mostly American-made military stock, it became increasingly reliant on “human wave” attacks, in which large numbers of infantry troops acted as cannon fodder to penetrate enemy defenses. The human wave attacks were predominantly carried out by the basij, who relied on Shi’a religious propaganda and established a cult of martyrdom to recruit boys as young as ten years old, mostly from peasant and working-class backgrounds, and to a lesser extent, elderly, unemployed men. The basij recruits would infamously clear enemy minefields by walking across them so that more regular infantry units could advance.

While Iran’s human wave tactics were employed successfully to demoralize Iraqi troops during the reconquest of its territory, they proved futile during the Iranian invasion of Iraq. Iraqi military planners with superior intelligence and knowledge of the terrain became adept at repelling the human waves, strategically retreating troops to draw the basij into easy “killing zones.” Between 1982 and 1985, numerous Iranian offensives resulted in Iran taking only small slivers of Iraqi territory while failing to achieve major objectives, such as capturing the major port city of Basra. Although Iran’s human wave strategy failed to gain territory and created large casualties, Khomeini continued to stonewall international demands for a ceasefire, defiantly telling critics, “These international bodies never ask this man who talks of peace why he attacked Iran.”

Within Iran, the continued usage of the human wave strategy emerged as a key issue for debate. IRGC Chief Mohsen Rezaei and majles speaker Rafsanjani, who had taken over from Khamenei as Khomeini’s representative on the Supreme Defense Council and was his most trusted civilian advisor on the war, were the most prominent advocates for continued mass infantry assaults. Many officers from Iran’s conventional forces, who were more conservative, argued that the human waves were unsustainable, a view shared by rivals Khamenei and Mousavi. The influence of Rezaei and Rafsanjani won out with Imam Khomeini, and Iran continued using the human wave strategy despite its futility. The IRGC’s influence within Iranian society also grew, with the force serving as an extension of and repository for additional clerical power. The commitment of its conscripts and volunteers to the revolution and willingness for martyrdom led Iran’s leadership to funnel most recruits, funds, and weaponry to the IRGC and basij, cementing their supremacy over the conventional forces by this point. Reflecting its growing prominence and permanence beyond the current conflict, the regime created a separate ministry for the IRGC, distinct from the defense ministry, and the group also began establishing its own air and naval forces.

In the spring of 1984, Iran held parliamentary elections, and the ongoing debates within Iran over the conduct of the war drove increasing IRP factionalism. The Islamic Left, helmed by Mousavi, increased its power within the IRP and emerged as the dominant faction within the majles. The Guardian Council – the 12-member deliberative body adjudicating whether all legislation complies with sharia and the Iranian Constitution – was dominated by conservatives and vetoed much of Mousavi’s agenda, leading to political stagnation and increasing tensions between the left and conservative factions.

By this point, the war's high casualties and deleterious economic effects were sapping Iranian morale within the armed forces and the civilian population. Ayatollah Khomeini stressed that revolutionary steadfastness and fighting against Western imperialism outweighed material comforts and continued prosecuting the war despite food and other shortages. Khomeini repeatedly rebuffed Saddam Hussein’s entreaties for a ceasefire, prompting Hussein in early 1984 to threaten attacks on the Iranian home front in response to Iran escalating its offensives within Iraq. Khomeini was unmoved, and Iraq began campaigns in early 1984 referred to as “the war of the cities” – aerial bombardments and ballistic missile attacks on Iranian cities and towns that killed thousands – and “the tanker war” – attacks on Iranian oil refineries, energy infrastructure, and commercial shipping vessels. These campaigns sowed terror by design, leading to further contractions of the Iranian economy and the loss of oil revenues. Iraq was able to carry out this targeting of Iranian civilians with virtual impunity, as Iran had to exercise caution in its responses and avoid carrying out blustery threats, such as closing the Strait of Hormuz to commercial shipping, to prevent the U.S. or other Western powers from more actively intervening in the conflict.

While the Iranian public faced numerous privations due to the ongoing war, Prime Minister Mousavi developed a reputation as a pragmatic and competent manager who stopped the situation from getting too out of hand. The turmoil of the 1979 revolution, followed by the initiation of the Iran-Iraq War, had created a dire economic situation. Iran’s foreign currency reserves had dropped from $14.6 billion at the onset of the revolution to about $1 billion by the end of 1981. One of Mousavi’s first duties was to revive oil production to offset these losses and meet the exigencies of wartime spending. He grew Iran’s oil revenues from $12 billion in 1981 to $19 billion in 1982 and 1983. However, Iran’s oil revenues fell to $6 billion annually by 1986 due to Iraq’s imposition of the tanker war. Unemployment within Iran reached nearly a peak of 50 percent.

Mousavi’s other primary task was implementing a ration card system, which earned him the nickname “coupon prime minister.” Mousavi’s management of this system ensured that despite Iran’s declining foreign currency reserves and oil revenues, massive wartime spending, sanctions, and a growing population, there were no food or other essentials shortages, and inflation remained low. Because the citizenry’s baseline needs were met, Khomeini’s calls for national sacrifice and austerity measures were rendered palatable, and national unity did not break down.

Given his central role in national planning, Mousavi recognized early into the Iranian invasion of Iraq that the high costs of the war were pushing the Iranian government to the breaking point. His radicalism waned, and he became more of a pragmatic than revolutionary manager, counselling that rapid, widespread revolutionary export was unrealistic. While Khomeini was unrelenting in his view of the war as necessary to uphold national cohesion and cement clerical control, he held Mousavi in high esteem for his managerial and economic prowess.