The Sectarian Machine: How the Sunni-Shia Divide Powers Empire
From a 7th-century succession dispute to the assassination of Iran’s Supreme Leader — how the United States, Israel, and regional powers weaponize Islam’s oldest fracture to reshape the Middle East.
Contents
- The Origins of the Divide
- Timeline: The Sectarian Split (632 CE – Present)
- Timeline: Iran’s Modern History — From Empire to Islamic Republic (1907 – 2026)
- The Modern Geopolitical Map
- How Each Stakeholder Exploits the Divide
- The Current Conflict — February 28, 2026
- The Deeper Pattern
- Sources & Further Reading
- → Part II: No Endgame — The Myth of Regime Change by Airstrike
The Origins of the Divide
The Sunni-Shia split originated in the 7th century as a political dispute over who should succeed the Prophet Muhammad after his death in 632 CE. Sunnis supported the selection of Abu Bakr, a close companion of the Prophet, as the first caliph. Shias believed leadership rightfully belonged to the Prophet’s family — specifically Ali ibn Abi Talib, his cousin and son-in-law. What began as a succession question calcified over centuries into distinct theological traditions, legal schools, and political identities.
Today, roughly 85–90% of the world’s Muslims are Sunni, while about 10–15% are Shia. Iran is the dominant Shia-majority state (approximately 90% Shia), while the Arab Gulf monarchies — Saudi Arabia, the UAE, Bahrain, Kuwait — are Sunni-led. Iraq has a Shia majority but was governed by Sunnis under Saddam Hussein until 2003. Lebanon, Bahrain, and Yemen all have significant Shia populations that exist under or alongside Sunni political power.
It is essential to understand: this is not a religious war in any meaningful theological sense. It is a political conflict that was dressed up as a sectarian one, and it has been exploited by every major power — internal and external — that seeks leverage in the region.
Timeline: The Sectarian Split
Death of Prophet Muhammad
The Prophet dies without naming an explicit successor. The Muslim community (ummah) splits over the question of leadership. The majority selects Abu Bakr as the first caliph; supporters of Ali ibn Abi Talib — the “Shi’at Ali” (partisans of Ali) — dissent.
OriginThe Rightly Guided Caliphs
Abu Bakr, Umar, and Uthman rule in succession. Ali finally becomes the fourth caliph in 656 but faces immediate civil war (the First Fitna). He is assassinated in 661. The caliphate passes to the Umayyad dynasty, permanently marginalizing Ali’s lineage from political power.
SuccessionThe Battle of Karbala
Ali’s son Hussein is killed by Umayyad forces at Karbala (modern Iraq). This massacre becomes the foundational trauma of Shia Islam — commemorated annually during Ashura. Karbala transforms the political dispute into a profound theological and identity marker: a narrative of righteous suffering against unjust power.
Foundational EventAbbasid Revolution
The Umayyads are overthrown by the Abbasids, who initially court Shia support by claiming descent from the Prophet’s family. Once in power, the Abbasids consolidate Sunni orthodoxy and suppress Shia political movements. Shia communities develop distinct jurisprudence and theology in response to continued marginalization.
Political FractureOccultation of the Twelfth Imam
Twelver Shias believe the 12th Imam, Muhammad al-Mahdi, entered “occultation” (hidden existence) and will return as the Mahdi to establish justice. This doctrine becomes central to Twelver Shia theology — the dominant branch in Iran, Iraq, and Lebanon — and shapes the concept of clerical authority governing in the Imam’s absence.
TheologyThe Fatimid Caliphate
The Ismaili Shia Fatimid dynasty rules North Africa and Egypt, establishing an alternative caliphate rivaling Sunni Abbasid Baghdad. This era demonstrates that the Sunni-Shia split is not just theological but a contest over political legitimacy and territorial control.
Rival CaliphateSafavid Dynasty — Iran Becomes Shia
Shah Ismail I establishes the Safavid Empire in Persia and mandates Twelver Shiism as the state religion. This is the single most important event in creating Iran’s Shia identity. The conversion was often coercive but established a permanent sectarian geography: Shia Iran against the Sunni Ottoman Empire to the west. The Sunni-Shia divide now maps onto imperial borders.
State ReligionGeopoliticsSafavid-Ottoman Rivalry
Two centuries of intermittent war between Shia Safavid Persia and Sunni Ottoman Turkey. The sectarian divide becomes the organizing principle of regional geopolitics — a template that persists to this day. Proxy battles, border populations forced to choose sides, and mutual demonization entrench the rift.
Imperial WarThe Iranian Revolution
Ayatollah Ruhollah Khomeini overthrows the US-backed Shah and establishes an Islamic Republic governed by Shia clerical authority (velayat-e faqih). This sends shockwaves through the Sunni Arab world — particularly Saudi Arabia, which now faces a revolutionary Shia state challenging its claim to Islamic leadership. The modern era of weaponized sectarianism begins.
RevolutionSectarianIran-Iraq War
Sunni-led Iraq under Saddam Hussein invades Shia Iran. The US and Gulf states back Iraq. An estimated 500,000–1,000,000 die. The war deepens the Sunni-Shia geopolitical fault line and establishes the template for external powers (the US, in particular) using the divide to contain Iran.
WarUS InvolvementUS Invasion of Iraq — Shia Empowerment
The US overthrows Saddam Hussein and, through de-Baathification, dismantles the Sunni power structure. Iraq’s Shia majority gains political control for the first time. Iran gains enormous influence in its neighbor. King Abdullah II of Jordan warns of a “Shia Crescent” stretching from Iran through Iraq to Lebanon. The sectarian civil war that follows kills hundreds of thousands.
US InterventionSectarian RealignmentArab Spring & Proxy Wars
Syria’s civil war, Yemen’s war, Bahrain’s suppressed uprising — each conflict maps onto the Sunni-Shia divide, with Saudi Arabia and Iran backing opposite sides. The region becomes a chessboard of sectarian proxy conflicts. ISIS rises in the vacuum, targeting Shias as apostates. Hezbollah fights in Syria. The Houthis take northern Yemen. The human cost is staggering.
Proxy WarsWeaponized DivideChina-Brokered Iran-Saudi Rapprochement
In a surprise move, China mediates a diplomatic normalization between Iran and Saudi Arabia. Embassies reopen. This briefly suggests the sectarian geopolitical framework might be weakening — and that non-Western powers could reshape the region’s dynamics. The thaw proves short-lived.
DiplomacyCollapse of the Axis of Resistance
Israel’s wars against Hamas and Hezbollah following October 7, 2023 significantly degrade Iran’s proxy network. The fall of Assad in Syria (December 2024) removes Iran’s key Arab state ally. Hezbollah is severely weakened. The Shia arc of influence from Tehran to Beirut — built over 40 years — begins to fracture. Iran’s primary tool for projecting power outside its borders is diminished.
WarAxis WeakenedUS-Israel Strike Iran — Khamenei Killed
The US and Israel launch Operation Roaring Lion / Epic Fury — a massive coordinated assault on Iran with the stated aim of regime change. Supreme Leader Ali Khamenei is killed. Iran retaliates against US bases across the Gulf and strikes Israel. Iran’s president declares it “a declaration of open war on Muslims, especially Shiites, in all corners of the world.” The entire sectarian architecture of the region convulses.
WarUS/IsraelRegional CrisisTimeline: Iran’s Modern History — From Empire to Islamic Republic
Understanding how Iran became an Islamic Republic requires tracing the repeated interventions of Western powers — particularly Britain and the United States — in Iranian sovereignty. The 1979 Revolution was not born in a vacuum; it was the culmination of decades of foreign interference, imposed autocracy, and popular frustration.
Anglo-Russian Convention
Britain and Russia divide Iran into spheres of influence without Iranian consent. The north goes to Russia, the south to Britain, with a neutral zone in between. Iran’s sovereignty is treated as secondary to European imperial competition. This sets the pattern of external powers treating Iran as a resource to be managed.
Foreign InterventionDiscovery of Oil
The Anglo-Persian Oil Company (later BP) discovers oil in southwestern Iran — the first major find in the Middle East. Britain immediately moves to secure control of this resource. Iran’s oil wealth becomes the primary reason for Western interest in the country and the primary driver of intervention for the next century.
Resource ExtractionBritish-Backed Coup — Rise of Reza Khan
With British encouragement, military officer Reza Khan seizes power. He later crowns himself Reza Shah Pahlavi in 1925, establishing the Pahlavi dynasty. The new shah modernizes Iran along Western lines but with authoritarian methods. Britain secures its oil interests through a compliant ruler.
Regime InstallationAnglo-Soviet Invasion
Britain and the Soviet Union invade Iran to secure supply lines during WWII and prevent potential Axis alignment. Reza Shah is forced to abdicate in favor of his young son, Mohammad Reza Pahlavi. Iran’s sovereignty is again overridden by great power interests. The new young Shah is initially weak and dependent on foreign support.
Invasion / Regime ChangeMossadegh & the Nationalization of Oil
Democratically elected Prime Minister Mohammad Mossadegh nationalizes Iran’s oil industry, directly challenging British profits. Mossadegh is a secular, democratic nationalist — not a religious figure. He is enormously popular. Britain imposes an oil embargo and lobbies the US for help. The Truman administration initially resists but the incoming Eisenhower administration is receptive, framing Mossadegh as a Communist threat in Cold War terms.
NationalizationPre-CoupOperation AJAX — CIA/MI6 Coup
The CIA, in partnership with British MI6, overthrows Mossadegh’s democratically elected government. The operation (AJAX by the CIA, Boot by MI6) uses bribed military officers, hired mobs, and propaganda to create chaos and remove Mossadegh. The Shah, who had briefly fled the country, returns to power as an absolute monarch. This is the single most consequential foreign intervention in Iranian history. It destroys Iran’s democratic movement, installs an authoritarian client state, and generates anti-American resentment that festers for 26 years.
CIA CoupDemocracy DestroyedThe Shah’s Authoritarian Rule
Mohammad Reza Shah rules as a US-backed autocrat. The CIA helps create SAVAK, Iran’s feared secret police, which tortures and kills dissidents. The Shah modernizes the economy and military with massive US support (including nuclear technology) but crushes all political opposition — liberal, leftist, and religious. The only institution with enough independence to organize resistance is the Shia clerical establishment, particularly in Qom. This is why the revolution, when it comes, is led by clerics rather than secular democrats — the CIA coup and SAVAK had eliminated all other opposition.
US Client StateRepressionKhomeini’s First Confrontation
Ayatollah Ruhollah Khomeini publicly denounces the Shah’s White Revolution reforms and US influence. He is arrested, sparking the June 1963 protests (15 Khordad uprising), which are violently suppressed. Khomeini is eventually exiled — first to Iraq, then to France — where he spends 15 years building a revolutionary network and developing the theory of velayat-e faqih (guardianship of the Islamic jurist): the theological framework for clerical rule that will govern post-revolution Iran.
ExileThe Islamic Revolution
Massive popular protests — millions in the streets — force the Shah to flee on January 16. Khomeini returns from exile on February 1 to ecstatic crowds. By February 11, the military declares neutrality and the monarchy collapses. The revolution is a broad coalition: Islamists, leftists, liberals, nationalists. But Khomeini and the clerical establishment rapidly consolidate power, sidelining and then crushing their secular allies. Iran becomes an Islamic Republic governed by Shia clerical authority. The US loses its most important regional ally.
RevolutionIran Hostage Crisis
Revolutionary students storm the US Embassy in Tehran and hold 52 Americans hostage for 444 days. The crisis is driven by fears that the US will repeat the 1953 coup. It permanently poisons US-Iran relations and entrenches mutual hostility. For Americans, it becomes a foundational grievance; for Iranians, it confirms the revolution’s anti-imperial stance.
Hostage CrisisIran-Iraq War
Saddam Hussein invades Iran with Gulf Arab financial backing and US intelligence support. The US provides Iraq with satellite imagery, military intelligence, and diplomatic cover — even after Iraq uses chemical weapons on Iranian soldiers and Kurdish civilians. The war kills an estimated 500,000–1,000,000. It solidifies the clerical regime’s hold on power (rallying nationalistic support) and deepens Iran’s perception that the US and Sunni Arab states are aligned against it.
WarUS Support for IraqUSS Vincennes Shoots Down Iran Air Flight 655
A US Navy cruiser shoots down an Iranian civilian airliner over the Persian Gulf, killing all 290 passengers — including 66 children. The US initially denies responsibility, then claims it was a mistake. The crew is later awarded combat medals. For Iranians, this incident exemplifies American impunity and indifference to Iranian life.
US Action“Axis of Evil”
President George W. Bush names Iran as part of an “Axis of Evil” alongside Iraq and North Korea. This comes just as Iranian reformists under President Khatami had been cooperating with the US on Afghanistan. The speech empowers Iranian hardliners who argue that engaging with America is futile. Iran’s nuclear program accelerates.
US HostilityDiplomacy KilledJCPOA (Iran Nuclear Deal)
After years of negotiations, the US, EU, and Iran reach a landmark nuclear agreement. Iran accepts strict limits on its nuclear program in exchange for sanctions relief. The deal is opposed by Israel, Saudi Arabia, and US hawks, who argue it legitimizes the Iranian regime and does not address its regional activities.
DiplomacyTrump Withdraws from JCPOA
President Trump unilaterally withdraws the US from the nuclear deal and imposes “maximum pressure” sanctions, devastating Iran’s economy. Iran responds by gradually exceeding nuclear limits. The withdrawal vindicates Iranian hardliners who argued the US could never be trusted as a negotiating partner — echoing 1953.
US WithdrawalAssassination of Qasem Soleimani
The US assassinates IRGC General Qasem Soleimani via drone strike in Baghdad. Soleimani was the architect of Iran’s regional proxy network. The killing is a major escalation — the first US assassination of a foreign government’s senior military leader in peacetime. Iran retaliates by striking US bases in Iraq.
US AssassinationEscalationMahsa Amini Protests
The death of Mahsa (Jina) Amini in morality police custody sparks the “Woman, Life, Freedom” movement — the largest protests since 1979. The regime responds with brutal repression, killing hundreds and imprisoning thousands. The protests reveal deep domestic opposition to theocratic rule but also the regime’s willingness to use lethal force to survive.
Protest MovementFirst Israel-Iran War (Twelve-Day War)
Israel and the US strike Iranian nuclear facilities during a twelve-day conflict. The strikes weaken but do not destroy Iran’s nuclear and missile programs. The IRGC and proxy networks survive. Iran’s leadership remains intact. The war establishes that direct military confrontation between Israel and Iran is no longer hypothetical.
WarProtests, Massacres, and Failed Nuclear Talks
The largest protests since the Islamic Revolution erupt. The regime massacres thousands of civilians. Simultaneously, indirect nuclear talks in Muscat and Geneva fail to produce agreement. Trump issues a 10-day deadline. The US masses military assets at levels not seen since 2003. The path to war is set.
ProtestsTalks FailOperation AJAX Redux — US and Israel Strike Iran
The US and Israel launch Operation Roaring Lion / Epic Fury — a massive coordinated assault aimed at regime change. Supreme Leader Khamenei and top military officials are killed in the opening strikes. Trump tells Iranians the country “will be yours to take.” The stated objectives: eliminate Iran’s nuclear and missile programs, destroy its navy, and change its leadership. Iran retaliates across the region. The cycle that began with the 1953 coup enters its most violent chapter.
US/Israel StrikesRegime ChangeThe Modern Geopolitical Map
The 1979 Iranian Revolution reconfigured the Middle East’s geopolitical architecture. Iran transformed from a US-backed monarchy into a revolutionary Shia theocracy that explicitly challenged both American hegemony and the Sunni Arab order. The new regime built what became known as the “Axis of Resistance” — a network of Shia (and some non-Shia) allies and proxies stretching across the region: Hezbollah in Lebanon, aligned militias in Iraq, the Assad government in Syria, and the Houthis in Yemen. This gave Iran strategic depth far beyond its borders and an asymmetric answer to the conventional military superiority of the US and its Gulf allies.
In response, Saudi Arabia and Iran became locked in a regional cold war, using the sectarian divide to further their ambitions. How their rivalry is settled shapes the political balance across the region — particularly in Syria, Iraq, Lebanon, Bahrain, and Yemen. It is also important to recognize that Iran is Persian, not Arab. It speaks Farsi and draws on an imperial history that predates Islam. Differences in ethnicity, language, and historical memory reinforce Tehran’s separateness from the Arab-majority Sunni states, compounding existing geopolitical rivalries.
How Each Stakeholder Exploits the Divide
United States
Aligned with Sunni Gulf monarchies as part of its energy security and counter-Iran strategy. A 2008 RAND Corporation study for the US military recommended “divide and rule” — taking the side of conservative Sunni regimes against Shia empowerment movements. The US maintains massive military infrastructure across Sunni states — bases in Qatar, Kuwait, Bahrain (the Fifth Fleet), the UAE, Jordan, Iraq, and Saudi Arabia — all framing Iran as the primary threat. The 2003 Iraq War inadvertently empowered Iraqi Shias and strengthened Iranian influence, which then became the justification for even deeper Sunni-state alignment with Washington.
Israel
Has long identified Iran as its primary strategic threat — because of Iran’s support for Hezbollah and Hamas and its nuclear program. Israel cultivated quiet and then increasingly open relationships with Sunni Gulf states based on shared antagonism toward Iran (the Abraham Accords). The sectarian divide is useful to Israel because Iran faces hostility not just from Israel and the US, but from its own Muslim neighbors. This is an election year in Israel, and Netanyahu’s close relationship with Trump strengthens him politically.
Saudi Arabia & Gulf States
Leverage Sunni identity and fear of Iranian expansionism to justify military spending, Western alliance structures, and suppression of domestic Shia dissent. In Bahrain, Saudi Arabia supports the Sunni monarchy against Shia opposition movements. In Yemen, it leads a coalition fighting Iranian-backed Houthis. The Gulf monarchies frame Iranian influence as an existential sectarian threat — which conveniently aligns their security interests with Washington’s. They now absorb Iranian retaliatory strikes on US bases within their borders.
Iran
Uses the sectarian network to project power asymmetrically. Rather than matching Gulf states’ conventional military spending (backed by the US), Iran invested in proxy forces and missile technology. It frames itself as the defender of oppressed Shia communities marginalized in Sunni-led states, which gives its influence a populist and ideological dimension beyond state power. The killing of Khamenei has been framed as “a declaration of open war on Muslims, especially Shiites, in all corners of the world.”
Turkey
Under Erdogan, Turkey has positioned itself as a leading Sunni power. It supports Syrian Sunni opposition and seeks to diminish Iranian influence, while competing with Saudi Arabia for leadership of the Sunni world. Turkey opposes an independent Kurdish state and occasionally finds tactical alignment with Iran on that issue, but the broader competition for Islamic leadership exacerbates tensions.
The Current Conflict — February 28, 2026
Operation Roaring Lion / Epic Fury
On February 28, 2026, Israel and the United States launched a coordinated joint attack on Iran — codenamed Operation Roaring Lion by Israel and Epic Fury by the US Department of Defense — targeting key officials, military commanders, and facilities, with the stated aim of regime change. The attack included the assassination of Supreme Leader Ali Khamenei, who was gathered with top military and intelligence leaders in the national security council offices.
Airstrikes began around 9:45 a.m. Tehran time (1:15 a.m. EST) on Saturday, February 28 — the first day of the Iranian work week. A combination of US missiles, drones, and Israeli fighter jets was used. CBS News reported that 40 Iranian officials were killed in the strikes. The US said it sunk an Iranian naval vessel. The Red Crescent reported 201 civilians killed and 747 injured by the end of the first day. A girls’ elementary school in Minab was struck, with reported casualties reaching 148.
The Prelude
Tensions intensified in January 2026 amid Iran’s massacres of civilians during the largest protests since the Islamic Revolution. By mid-January, the US began amassing air and naval assets at levels not seen since 2003. Indirect nuclear talks in Muscat and Geneva failed. On February 20, Trump issued a 10-day deadline for a deal. When the third round of negotiations proved unsatisfactory, the strikes began.
Iran’s Retaliation
Iran launched waves of missiles and drones at Israel and at US military bases across the Middle East. The IRGC says it attacked 27 bases where US troops are deployed. Iranian missiles targeted Saudi Arabia (Riyadh and Eastern Province oil infrastructure), Kuwait, Bahrain’s US naval base, Qatar’s Al Udeid base, and the UAE. Jordan intercepted 49 drones and ballistic missiles. Kuwait’s international airport was hit by a drone. Dubai International Airport — the world’s busiest for international flights — shut down indefinitely. Four US service members have been killed.
The Sectarian Dimension
Iran is treating the Sunni Gulf states’ hosting of American forces as complicity — which, from a military standpoint, it functionally is. This is exactly where the Sunni-Shia divide becomes operationally decisive. Gulf states that had been on a path of rapprochement with Iran are now forced to reassess. Their territory is being used as a launchpad for US operations, and they are absorbing Iranian retaliatory strikes.
Iran’s president declared the killing of Khamenei “a declaration of open war on Muslims, especially Shiites, in all corners of the world” — explicitly framing the conflict in sectarian terms. In Pakistan, at least nine protesters were killed storming the US Consulate in Karachi. In parts of Iran, cheers were heard after Khamenei’s death, while pro-regime crowds gathered in Tehran to mourn — revealing deep internal divisions within Iran itself.
Hezbollah condemned the strikes but fell short of announcing direct involvement — a sign that the degradation of Iran’s proxy network (after the fall of Assad, the weakening of Hezbollah and Hamas) limits Iran’s ability to activate its sectarian network. Lebanon’s political leadership proclaimed it does not need Hezbollah to defend Lebanese sovereignty.
The Deeper Pattern
What this conflict exposes is that the Sunni-Shia divide functions less as a genuine religious war and more as a geopolitical operating system. The US and Israel are not the only actors supporting regime change in Iran — Turkey, Azerbaijan, and Sunni Arab states would also benefit. For the US, regime change would make it the sole significant player in the region, minimizing the influence of the Russian-Chinese axis on oil and Middle East politics.
A weakened Iran means the neutralization of what Netanyahu has called Israel’s biggest regional foe for over a decade, and the potential end of the “axis of resistance.” For Sunni Gulf states, it removes their primary regional competitor. For the US, it consolidates a security architecture decades in the making.
The displacement and humanitarian dimensions of this conflict will be enormous. Iran has a population of 88 million. The disruption to Gulf economies, transit routes, energy markets, and refugee flows will have cascading effects well beyond the region. The cycle that began when the CIA overthrew Mossadegh in 1953 — destroying Iranian democracy and setting in motion the chain of events that produced the Islamic Republic — now enters its most violent chapter.
Sources & Further Reading
- Council on Foreign Relations — Impact Assessment cfr.org — Gauging the Impact of Massive U.S.-Israeli Strikes on Iran
- Council on Foreign Relations — Backgrounder cfr.org — The Sunni-Shia Divide
- Al Jazeera — Live Tracker aljazeera.com — Death Toll and Injuries Live Tracker
- CNN — Live Updates cnn.com — February 28, 2026 US-Israeli Strikes on Iran
- PBS NewsHour — Live Updates pbs.org — U.S. and Israel Attack Iran
- CBC News — Analysis cbc.ca — A Diminished Iran Would Redraw the Middle East
- Századvég — Strategic Analysis szazadveg.hu — Iran and the Shia-Sunni Power Struggle
- Wikipedia — Conflict Overview en.wikipedia.org — 2026 Iran Conflict
- Wikipedia — Prelude en.wikipedia.org — 2026 Iran-United States Crisis
- Wikipedia — Shia-Sunni Relations en.wikipedia.org — Shia-Sunni Relations
- CIA / Mossadegh — Historical en.wikipedia.org — 1953 Iranian Coup d’État