The Genesis of a Ruinous War: A Multi-Causal Analysis of Iraq’s 1980 Invasion of Iran

Abstract

This report provides an exhaustive analysis of the multifaceted causes behind Iraq’s invasion of Iran on September 22, 1980.

It argues that the war was not the result of a single grievance but a confluence of factors: deep-seated historical and territorial disputes, primarily over the Shatt al-Arab waterway; the transformative and threatening impact of the 1979 Iranian Revolution, which posed a direct ideological and sectarian challenge to the Iraqi regime; the personal ambitions and strategic miscalculations of Iraqi President Saddam Hussein, who sought both regional hegemony and the survival of his Ba’athist government; a perceived window of military opportunity created by post-revolutionary chaos in Iran; and a permissive international and regional environment.

By dissecting each of these causal layers and their interplay, this report concludes that the invasion was a product of Saddam Hussein’s paradoxical fusion of profound insecurity and supreme overconfidence, a fateful decision that unleashed one of the longest and most destructive conventional wars of the 20th century.

Part I: The Weight of History: Enduring Rivalries and a Humiliating Peace

The Iraqi invasion of Iran in September 1980 was not a spontaneous act of aggression but the violent culmination of historical rivalries that spanned centuries.

The roots of the conflict lay in unresolved territorial disputes, ethnic tensions, and a legacy of political maneuvering that left Iraq’s leadership with a deep-seated sense of grievance and a desire for vengeance.

Central to this history was the contest for control over the Shatt al-Arab waterway, a dispute that became inextricably linked with internal security challenges and the personal honor of Iraq’s leader, Saddam Hussein.

The Contested Waterway: The Shatt al-Arab as a Locus of Conflict

The struggle for control over the borderlands between modern-day Iran and Iraq is a historical constant, dating back to the Ottoman-Persian Wars of the 16th and 17th centuries.¹

While the 1639 Treaty of Zuhab established early frontiers, the Shatt al-Arab waterway—formed by the confluence of the Tigris and Euphrates rivers—remained a persistent source of friction.¹

The waterway was of immense strategic importance; for Iraq, it was the country’s sole outlet to the Persian Gulf, a vital artery for transportation and oil exports.⁴

For Iran, it was a critical channel for oil produced in its southwestern region.⁴

Throughout the 20th century, a series of treaties attempted to resolve the dispute, often reflecting the shifting balance of power.

The 1913 Constantinople Protocol and subsequent 1914 border commissions generally favored Ottoman, and later Iraqi, control.⁶

Following Iraq’s independence, the 1937 Treaty reaffirmed Iraqi sovereignty over most of the waterway, establishing the border on the river’s eastern Bank. It granted Iran an exception only for a four-mile anchorage zone near its major port and refinery at Abadan, where the boundary was set at the

thalweg—the median line of the main navigational channel.²

This arrangement brought a period of relative calm.¹

The situation changed dramatically following the 1968 Ba’athist coup in Iraq.

By this time, Iran, under Shah Mohammed Reza Pahlavi, had developed into a formidable regional military power.

In April 1969, the Shah’s government unilaterally abrogated the 1937 treaty, demanding the border be redrawn entirely along the thalweg principle.

Iran ceased paying tolls to Iraq and began escorting its tankers with warships.¹

Iraq, the militarily weaker state, declared the move a violation of international law but was powerless to stop it.¹

This act inaugurated a period of acute hostility and proxy warfare.

Iraq began fomenting separatist sentiment among the ethnic Arab population of Iran’s oil-rich Khuzestan province, while Iran, in a decisive retaliatory move, dramatically increased its support for Iraq’s rebellious Kurdish population, providing arms, funding, and safe haven with the backing of the United States and Israel.²

The 1975 Algiers Agreement: A Humiliation to be Avenged

The proxy conflict escalated into direct, armed border clashes between March 1974 and March 1975.²

Iran, possessing what was then the world’s fifth-largest military, used its superior air power to inflict a decisive defeat on Iraqi forces.²

Crippled by the military defeat and the debilitating, Iranian-backed Kurdish insurgency, Saddam Hussein—then Vice-Chairman of Iraq’s Revolutionary Command Council (RCC) but the country’s effective ruler—was forced to make concessions.²

At an OPEC summit in Algiers on March 6, 1975, Saddam and the Shah signed the Algiers Agreement, a pact that represented a major strategic victory for Iran and a profound humiliation for Iraq.³

Under the terms of the accord, Iraq conceded to Iran’s primary demand: the border in the Shatt al-Arab was redrawn along the thalweg line, effectively ceding control of half the waterway.²

In return, Iran agreed to cease all support for the Iraqi Kurds and secure its border against “subversive” activities.²

The impact was immediate.

Deprived of Iranian support, the Kurdish rebellion collapsed, leaving the population to face the full wrath of the Ba’athist regime.⁹

For Saddam Hussein, the Algiers Agreement was a stain on his honor and that of his nation, a concession extracted from a position of weakness.³

It was a strategic defeat that he was determined to one day reverse.³

Although the agreement was formalized in subsequent treaties, the “spirit of Algiers” quickly evaporated, with Iran accusing Iraq of reneging on other security-related promises by the end of 1975.⁹

The waterway dispute was not merely a territorial issue; it had become a symbol of national humiliation, directly linking Iraq’s sovereignty to its internal ethnic conflicts and the personal prestige of its leader.

The 1979 Iranian Revolution would provide what Saddam perceived as the perfect opportunity to violently erase the memory of 1975.

Part II: The Revolutionary Catalyst: A New and Threatening Regional Order

If historical grievances provided the combustible material for war, the 1979 Iranian Revolution was the spark that ignited the flame.

The revolution fundamentally altered the regional balance of power, replacing a familiar rival with a radical, ideologically hostile regime that posed a direct and existential threat to the Ba’athist state in Iraq.

This transformation provided Saddam Hussein with both a powerful motive—fear—and a compelling public justification for launching a preemptive war.

The Fall of the Shah and the Rise of Khomeini: A Geopolitical Earthquake

The overthrow of Shah Mohammed Reza Pahlavi in February 1979 was a geopolitical earthquake that sent shockwaves across the Middle East.

It removed a pro-Western, secular monarchy that, despite its rivalry with Iraq, had been a pillar of the regional status quo.¹⁵

In its place rose a revolutionary Shia theocracy led by Ayatollah Ruhollah Khomeini, a figure with whom Saddam Hussein had a history of deep personal animosity.¹⁷

Khomeini had spent over a decade in exile in the Iraqi holy city of Najaf, where the Ba’athist regime had initially tolerated and even supported his activities against their shared enemy, the Shah.²⁰

However, in a move to appease the Shah as part of the 1975 Algiers Agreement, Saddam expelled Khomeini in 1978.

This act, occurring just before Khomeini’s triumphant return to Iran, was a monumental political blunder that forged an implacable hatred between the two leaders.¹⁹

The Doctrine of Exporting Revolution: A Direct Threat to the Ba’athist State

Upon taking power, the Khomeini regime made its intentions clear.

On February 11, 1979, Khomeini proclaimed, “We will export our revolution to the four corners of the world”.¹⁷

This was not abstract rhetoric but a direct declaration of ideological war.

The new Iranian doctrine explicitly targeted secular, pan-Arab nationalism—the core ideology of Saddam’s Ba’ath Party—as an illegitimate force that must be “eradicated, or subjugated” in the name of a higher Islamic unity.¹⁷

Iraq, with its large Shia population and proximity, became the primary target for this revolutionary export.¹⁷

Almost immediately, Tehran began a systematic campaign of subversion aimed at toppling the Ba’athist government.²⁰

This campaign included:

• Sponsorship of Unrest: Iran instigated and funded a series of demonstrations and violent clashes in Iraq’s Shia holy cities of Najaf and Karbala throughout 1979 and into 1980.¹⁷
• Propaganda Warfare: Iran beamed Arabic-language radio broadcasts into Iraq, calling on the Iraqi people and, pointedly, members of the military to rise up and overthrow Saddam Hussein.²³
• Support for Militancy: Tehran provided crucial support to the Iraqi Shia Islamist group, the Dawa Party. This support culminated in a Dawa-led assassination attempt on Iraqi Deputy Prime Minister Tariq Aziz in April 1980.¹⁸

Saddam’s regime responded to this escalating campaign with characteristic brutality.

Security forces were dispatched to quell the uprisings, martial law was imposed in southern cities, and a fierce crackdown was launched against Shia activists.¹⁷

Iraq’s leading Shia cleric, Ayatollah Mohammad Baqir al-Sadr, who had connections to Khomeini, was placed under house arrest and, following the attack on Tariq Aziz, was executed along with his sister.¹⁷

Saddam’s government also began the forced expulsion of tens of thousands of Iraqi Shias who were accused of having Persian ancestry.¹⁷

This vicious cycle of Iranian incitement and Iraqi repression meant that a low-intensity, undeclared war was already well underway long before the formal invasion of September 1980.

The Sectarian Fault Line: Weaponizing the Sunni-Shia Divide

The Iranian threat was particularly potent because it exploited Iraq’s primary domestic vulnerability: its sectarian makeup.

Iraq was governed by a secular, Arab nationalist regime dominated by the Sunni minority, while the majority of the population—an estimated 65%—was Shia.¹⁷

This long-suppressed majority represented a potential source of insurrection that the Ba’ath party had managed through a combination of patronage and ruthless coercion.¹⁷

The success of a Shia-led revolution in neighboring Iran threatened to upend this fragile balance.

It was feared that Khomeini’s victory would “inspire insurgency among Iraq’s long-suppressed Shi’i majority”.¹

As a revered Shia religious figure, Khomeini’s calls for revolt carried a dangerous legitimacy among many Iraqi Shias that Saddam’s secular regime could not match.

The conflict was thus framed by both sides as an existential struggle between two irreconcilable ideologies: Persian Shia theocracy and Arab secular nationalism.²²

From the perspective of the Ba’athist leadership in Baghdad, the war had already begun.

Iran’s campaign of subversion was not a series of minor provocations but the opening phase of a revolutionary war aimed at the regime’s destruction.

Faced with an unceasing ideological assault that was difficult to counter without risking a full-scale civil war, Saddam chose to reframe the conflict.

By launching a conventional military invasion, he sought to escalate the fight from a battle for the “hearts and minds” of Iraqi Shias—a contest where he was vulnerable—to a war of armies and territory, a domain where he believed he held a decisive advantage.

The invasion of September 22, 1980, was therefore not the start of the conflict, but a dramatic and ultimately catastrophic attempt to seize the initiative and fight the war on Iraq’s own terms.

Part III: The Mind of the Aggressor: Saddam Hussein’s Strategic Calculus

The decision to invade Iran was ultimately made by one man: Saddam Hussein.

His strategic calculus was a complex and paradoxical mixture of profound insecurity and supreme overconfidence.

The invasion was driven by the twin imperatives of ensuring his regime’s survival against an existential revolutionary threat and seizing a golden opportunity to establish Iraq as the undisputed hegemon of the Persian Gulf.

This ambition was underpinned by a gross miscalculation of Iran’s resilience and the true costs of war.

The Dictator’s Twin Imperatives: Ambition and Survival

Saddam Hussein’s political life was forged in conspiracy and a ruthless pursuit of power.¹⁷

After years of operating as the strongman behind the scenes, he formally consolidated his absolute authority in July 1979, assuming the titles of President, Chairman of the RCC, and Prime Minister.

His first act was to orchestrate a purge of the Ba’ath Party, executing dozens of senior officials and eliminating any potential rivals.¹⁷

For Saddam, who had built his rule on an extensive secret police establishment and a pervasive personality cult, the survival of the Ba’athist regime was indivisible from his own personal survival.¹⁷

His decision to go to war reflected this fusion of personal and state interests.

It was a preventive war, designed to neutralize the existential threat posed by Khomeini’s revolutionary ideology before it could fatally destabilize Iraq from within.¹⁵

Yet, it was simultaneously a war of

opportunism and ambition.

The chaos in Iran presented a unique chance to punish a regional rival, seize valuable territory and resources, and achieve long-held geopolitical goals.¹⁵

While scholars debate whether fear or ambition was the primary driver, the evidence suggests they were two sides of the same coin; the opportunity to attack a weakened Iran appeared to be the perfect solution to the threat posed by a hostile Iran.²³

The Geopolitical Prize: Hegemony, Oil, and “Arabistan”

Saddam’s ambitions extended far beyond Iraq’s borders.

With Egypt’s 1979 peace treaty with Israel leading to its ostracism from the Arab League, a leadership vacuum had opened in the Arab world.

Saddam saw himself as the natural successor to Egypt’s Gamal Abdel Nasser, and he sought to make Baghdad the new political center of the Arab world.¹⁵

A swift and decisive military victory over non-Arab, Persian Iran would be the ultimate demonstration of his power and would cement his status as the foremost champion of pan-Arab nationalism.²¹

A key objective of the invasion was the conquest of Iran’s southwestern Khuzestan province, a region with a large ethnic Arab population that Iraqi propaganda referred to as “Arabistan”.²¹

The seizure of Khuzestan served multiple strategic purposes:

• Economic Gain: The province produced the majority of Iran’s oil. Capturing it would deliver a crippling economic blow to Tehran while providing a massive financial windfall for Baghdad. Some analyses posit that this oil grab was the single most important motive for the invasion.¹⁷
• Strategic Buffer: Control over Khuzestan would create a vital buffer zone, protecting Iraq’s vulnerable economic heartland and major cities like Basra from Iranian military pressure and ideological influence.¹⁷
• Bargaining Chip: Even if the invasion failed to topple the Khomeini regime, the occupation of Khuzestan would serve as a powerful bargaining chip to compel Iran to cease its attempts to export its revolution.¹⁷

The invasion was also intended to achieve the subsidiary goals of formally abrogating the 1975 Algiers Agreement, reclaiming full sovereignty over the Shatt al-Arab waterway, and “liberating” the predominantly Arab-populated Iranian cities of Khorramshahr and Abadan, all of which would further enhance Saddam’s prestige in the Arab world.¹⁷

The Window of Opportunity: A Critical Miscalculation

Saddam’s ambitious plans were predicated on a critical assumption: that Iran was too weak to fight back effectively.

The 1979 Revolution had plunged the country into internal chaos, and Iraqi intelligence concluded that the moment was ripe for a quick, low-cost victory.¹

Iran’s military, once the Shah’s formidable “gendarme of the Gulf,” appeared to be a hollowed-out force.²¹

The new clerical regime in Tehran, deeply suspicious of the loyalty of the Shah’s officer corps, had carried out extensive purges.

Thousands of experienced military personnel, from senior generals to skilled fighter pilots, were executed, imprisoned, or dismissed.¹⁹

These purges were accelerated after a failed coup attempt by air force officers in July 1980.²⁸

The regular army, or

Artesh, suffered from a near-total breakdown of its command structure and discipline, with non-commissioned officers forming councils to run military bases.²⁸

Compounding this, the provisional government had reduced the term of military conscription, further shrinking the army’s available manpower.²⁸

Saddam Hussein’s gravest mistake was to misjudge the nature of the war he was initiating.¹⁷

He and his generals planned for a limited, conventional conflict that they believed would last no more than a week and would likely trigger the collapse of the Khomeini regime.¹⁵

An examination of the military balance on the eve of the war shows the basis for this confidence.

Table 1: Comparative Military Strength, Iran and Iraq (September 1980)

Metric	Islamic Republic of Iran	Republic of Iraq
Active Soldiers	110,000–215,000	200,000–210,000
Tanks (Total/Operable)	1,700–2,100 / 500–1,150	1,750–2,800
Armored Vehicles (Total/Operable)	1,000–1,900 / 1,300	2,350–4,000
Artillery Pieces	300–1,100	1,350–1,400
Fighter-Bombers (Total/Operational)	421–485 / 200–205	295–380
Source: 26

While Iran possessed a large number of advanced American-made weapons on paper, the purges and the cut-off of US spare parts meant that only a fraction were operational.

Iraq held a clear advantage in operable tanks, armored vehicles, and artillery.²⁶

From a purely material standpoint, the Iraqi leadership had reason for optimism.

However, this calculus fatally ignored the intangible factors of ideology and nationalism.

The invasion did not cause the Iranian regime to collapse; instead, it galvanized the Iranian people and allowed Khomeini to rally the nation against a foreign aggressor.

The regime mobilized hundreds of thousands of zealous but poorly trained volunteers from the Islamic Revolutionary Guard Corps (IRGC) and the Basij militia, who fought with a tenacity that stunned the Iraqis.¹⁹

The Iraqi offensive, which initially made rapid gains, bogged down within three months, heralding a long and bloody war of attrition.¹

The Pre-War Economic Divide: Confidence vs. Chaos

The military miscalculation was compounded by an economic one, fueled by the stark contrast between the two nations’ economies in 1980.

On the eve of the war, Iraq was at the peak of its economic power.

Thanks to soaring oil prices, its oil revenues were projected to reach a record $30 billion in 1980, and the country had amassed enormous foreign exchange reserves estimated at $35 billion.¹⁵

By 1980, Iraq boasted the second-largest economy in the Arab world and was pouring its wealth into ambitious infrastructure and development projects.²⁹

Iran, meanwhile, was in economic turmoil.

The revolution had been preceded by massive capital flight and was followed by widespread strikes that crippled its vital oil industry, triggering the 1979 global oil shock.³¹

Iran’s GDP plummeted by over 10% in 1979 alone.³⁴

The new regime’s chaotic nationalization of banks, insurance companies, and major industries, coupled with the replacement of experienced technocrats with revolutionary loyalists, led to a disastrous fall in production and soaring inflation.³⁵

Table 2: Pre-War Economic Indicators, Iran vs. Iraq (c. 1979-1980)

Metric	Iran (Post-Revolution)	Iraq (Pre-War)
Annual Oil Revenue (1979/80)	Sharply reduced from pre-revolution levels	$27 billion (1980)
Foreign Exchange Reserves	Depleted by capital flight	~$35 billion
GDP Trend (1979)	Declined by over 10%	Strong growth
Oil Production Trend	Crippled by strikes and instability	Peaked at 3.5 million bpd
Economic Outlook	Turmoil, nationalization, managerial chaos	Ambitious development, “wonderfully well”
Sources: 15

This economic disparity bolstered Saddam’s confidence.

He believed a short, victorious war was not only affordable but would be a net economic gain after the seizure of Khuzestan’s oil fields.¹⁵

He failed to foresee the ruinous cost of an eight-year war of attrition, which would completely drain Iraq’s reserves and saddle the country with a foreign debt of more than $40 billion, a burden that would directly contribute to his next fateful decision: the invasion of Kuwait in 1990.²¹

Saddam’s decision-making process reveals a classic pathology of authoritarian rule.

His personal ambition and his regime’s survival were fused into a single interest.¹⁷

His intelligence services and advisors, including expatriate Iranian generals, likely fed him the optimistic assessments he wanted to hear, confirming his pre-existing biases about Iranian weakness.²⁰

This created an echo chamber that focused on Iraq’s tangible advantages in military hardware while ignoring the intangible but ultimately decisive strengths of its adversary.

The invasion was therefore not just a strategic error but a systemic failure of a regime where absolute power prevented rigorous analysis and made a catastrophic miscalculation all but inevitable.

Part IV: The International Arena: A Permissive Geopolitical Environment

Saddam Hussein’s decision to invade Iran was not made in a geopolitical vacuum.

It was enabled by a regional and international environment in which the world’s most powerful actors were either unwilling to prevent the conflict or actively, if tacitly, encouraged it.

Neither of the Cold War superpowers, nor the wealthy monarchies of the Persian Gulf, had any interest in the success of Iran’s revolutionary regime.

This created a permissive context for Iraqi aggression, with Baghdad positioning itself as a convenient instrument to contain and punish Tehran.

The Superpowers’ Stance: Tacit Approval and Strategic Calculation

At the time of the invasion, both the United States and the Soviet Union viewed revolutionary Iran as a source of instability, leading them to adopt policies that ultimately favored Iraq.

For the United States, relations with Iran had reached a nadir following the seizure of the U.S. embassy in Tehran in November 1979 and the ensuing hostage crisis.¹⁹

The new Islamic Republic was regarded as a pariah state.

While the official U.S. policy towards the war was one of neutrality, the overriding strategic objective was to prevent an Iranian victory.³⁷

This sentiment was famously captured by diplomat Henry Kissinger’s remark, “It’s a pity they both can’t lose”.³⁷

As the war progressed and Iran gained the upper hand, this neutrality evolved into a clear tilt towards Iraq.

The U.S. provided Saddam’s regime with billions of dollars in economic aid, dual-use technology that had military applications, satellite intelligence, and operational training.²¹

While a popular theory, particularly in the Arab world, alleges that Washington gave Saddam a direct “green light” to invade, no definitive proof has ever emerged.

Nevertheless, the intense American hostility towards Iran created an environment where Saddam could confidently assume that the U.S. would not intervene to stop his invasion.³⁷

The Soviet Union faced a more complex dilemma.

Iraq was a long-standing client state, bound to Moscow by a 1972 Treaty of Friendship and Cooperation and serving as a major purchaser of Soviet arms.²⁶

The war was inconvenient, however, as Moscow also hoped to court the new, fiercely anti-American regime in Iran.³⁸

Consequently, the USSR initially declared a policy of “strict neutrality” from 1980 to 1982, even temporarily halting major arms sales to Iraq and permitting its allies, Syria and Libya, to supply weapons to Iran.³⁸

This changed decisively after 1982, when Iranian forces pushed into Iraqi territory and threatened to topple Saddam’s government.

Fearing the collapse of a key ally and the potential spread of revolutionary Islam to its own Muslim-majority republics in Central Asia, Moscow shifted to a policy of robust support for Iraq.³⁸

In the war’s later stages, the USSR became Iraq’s most important military supplier, providing massive quantities of tanks, aircraft, and missiles that were crucial to stalling the Iranian advance.³⁸

The Arab Reaction: Fear and Financial Fortification

For the conservative monarchies of the Persian Gulf, particularly Saudi Arabia and Kuwait, Khomeini’s revolutionary ideology was a terrifying and immediate threat.

They feared that Iran’s call to export its revolution would incite their own Shia populations and destabilize their rule.¹⁷

In this context, they saw Saddam Hussein’s secular, Arab nationalist Iraq as a vital bulwark against Persian and Shia expansionism—an “Arab shield” that could blunt the force of the Iranian Revolution.⁴³

While maintaining a facade of neutrality, these Gulf states became Iraq’s primary financiers.

They provided massive and indispensable support to the Iraqi war effort ²¹:

• Financial Aid: Saudi Arabia and Kuwait provided Iraq with loans estimated to be as high as $50 billion over the course of the war. They also sold oil on Iraq’s behalf to help generate revenue.⁴³ In 1982 alone, the Gulf states provided an estimated $24 billion in aid to Baghdad.⁴³
• Logistical Support: They granted Iraq access to their ports on the Red Sea and overland transport routes, allowing military equipment and other vital goods to reach Iraq while bypassing the contested waters of the Persian Gulf.⁴³

This support was not an act of charity but a strategic investment in their own security.

By bankrolling Saddam’s war, the Gulf monarchies were effectively outsourcing their defense to Baghdad.

In stark contrast, the only Arab states to support Iran were Syria and Libya, whose rival Ba’athist and revolutionary regimes, respectively, were hostile to Saddam’s Iraq.³⁸

The Kurdish Factor: A Persistent Proxy Battleground

The Kurdish populations in both Iran and Iraq were used as pawns by both regimes.

Having been betrayed by the Shah in the 1975 Algiers Agreement, the leadership of Iraq’s Kurdish insurgency saw the 1980 war as a new opportunity.

Adhering to the maxim “the enemy of my enemy is my friend,” they allied themselves with Khomeini’s Iran, launching a guerrilla war against the Ba’athist regime in northern Iraq.¹⁴

This alliance meant that Iraq was forced to fight a two-front war from the outset: against the Iranian military in the south and against Iranian-backed Kurdish rebels in the north.

The Kurdish national movement posed a continuous and serious threat to the Iraqi state throughout the conflict.¹⁴

This collaboration proved catastrophic for the Kurdish people.

Saddam’s regime viewed them as a fifth column and retaliated with unimaginable brutality.

This culminated in the 1988 Anfal Campaign, a genocidal operation that involved the systematic destruction of thousands of Kurdish villages and the widespread use of chemical weapons.

An estimated 180,000 Kurdish civilians were killed in the campaign.¹⁴

True to form, at the war’s conclusion, Iran once again abandoned the Kurds in the interest of reaching an accommodation with Baghdad.¹⁴

The international and regional context thus created a uniquely permissive environment for war.

The superpowers saw an opportunity to let two troublesome states bleed each other dry, while the Gulf monarchies saw Iraq as a proxy army to fight a war they could not fight themselves.

This backing was a critical enabling factor, giving Saddam Hussein the confidence that his invasion would be met not with international condemnation and isolation, but with tacit approval and material support.

Part V: Synthesis and Conclusion: The Confluence of Causes

The decision by Iraq to invade Iran in September 1980 was not the product of a single cause but of a fatal confluence of historical grievance, ideological threat, personal ambition, and strategic miscalculation, all occurring within a permissive international environment.

To understand the war’s genesis is to understand how these distinct factors converged and reinforced one another in the mind of Saddam Hussein, making an otherwise unthinkable conflict seem both necessary and opportune.

Defensive Preemption or Offensive Opportunism? A False Dichotomy

Scholarly debate has often framed the motive for the invasion as a choice between defensive preemption and offensive opportunism.

This, however, is a false dichotomy.

The war was an inseparable fusion of both.

The threat from revolutionary Iran was genuine and, from the perspective of the Ba’athist regime, existential.¹⁵

Tehran’s active campaign to incite Iraq’s Shia majority and overthrow Saddam’s government constituted a real and present danger, lending the invasion a powerful defensive logic.

At the same time, the invasion was undeniably an act of opportunistic aggression.

Saddam’s long-held ambitions for regional hegemony, the revanchist desire to erase the humiliation of the 1975 Algiers Agreement, and the strategic goal of annexing the oil-rich Khuzestan province were potent offensive drivers.¹⁵

The key to understanding the decision for war lies in recognizing how the opportunity presented by a weakened, chaotic Iran seemed to be the perfect solution to the threat posed by a hostile, revolutionary Iran.

In Saddam’s strategic calculus, the invasion was a masterstroke that could solve his security problem while simultaneously achieving his hegemonic ambitions.

The Point of No Return: The Abrogation of the Algiers Agreement

The symbolic point of no return came on September 17, 1980, five days before the full-scale invasion.

In a televised address, Saddam Hussein dramatically tore up a copy of the 1975 Algiers Agreement, declaring it “null and void”.²

He justified this act by claiming that Iran, through its constant subversion and interference, had already violated the treaty’s core principles of good neighborliness and non-interference.⁷

This theatrical gesture was the public culmination of all the war’s underlying causes.

It was a rejection of a humiliating historical treaty, a formal break with the revolutionary regime that had threatened his rule, a signal of Iraq’s newfound strength, and a reflection of his belief that Iran was too weak to enforce the treaty’s terms.

It wrapped all of Iraq’s complex motivations—historical, ideological, personal, and opportunistic—into a single, legally-framed pretext for a war that had, in reality, already been decided.

Legacy of a Fateful Decision

The invasion, born from this toxic brew of fear and ambition, was a strategic blunder of historic proportions.

The war failed to achieve any of Iraq’s primary objectives.

• It did not lead to a quick victory or the collapse of the Khomeini regime. On the contrary, the shared threat of a foreign invasion allowed the Islamic Republic to consolidate its power, rally a fractured population around the flag, and entrench hard-line institutions like the Islamic Revolutionary Guard Corps (IRGC).²¹
• It did not result in the annexation of Khuzestan or a permanent Iraqi takeover of the Shatt al-Arab. After eight years of horrific bloodshed, with casualties estimated at over one million killed on both sides, the war ended in a bloody stalemate.¹⁹ The 1988 UN-brokered ceasefire essentially returned both countries to the
  status quo ante bellum—the very borders defined by the 1975 Algiers Agreement that Saddam had sought to destroy.⁹
• It did not anoint Saddam as the leader of the Arab world. Instead, it left Iraq economically shattered, burdened with over $65 billion in war debts, and with more than 100,000 of its soldiers dead.¹⁷ This economic desperation was a direct cause of Saddam’s next catastrophic miscalculation: the invasion of Kuwait in 1990, which would set Iraq on a path to international isolation, further war, and eventual state collapse.²¹

Ultimately, the decision to invade Iran was a tragedy born of a dictator’s hubris.

It was a war launched to secure a regime and fulfill an ambition, yet it achieved the opposite, reinforcing the very revolutionary forces it sought to destroy while setting its own nation on a course for ruin.

The Iran-Iraq War stands as a grim testament to how historical rivalries, ideological fervor, and the flawed calculations of an authoritarian leader can converge to unleash a conflict of unimaginable cost and consequence.

Works cited

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