The Sunni-Shia Divide

Sectarian conflict is becoming entrenched in a growing number of Muslim countries and is threatening to fracture Iraq and Syria. Tensions between Sunnis and Shias, exploited by regional rivals Saudi Arabia and Iran, could reshape the future Middle East.

An ancient religious divide is helping fuel a resurgence of conflicts in the Middle East and Muslim countries. Struggles between Sunni and Shia forces have fed a Syrian civil war that threatens to transform the map of the Middle East, spurred violence that is fracturing Iraq, and widened fissures in a number of tense Gulf countries. Growing sectarian clashes have also sparked a revival of transnational jihadi networks that poses a threat beyond the region.

Islam’s schism, simmering for fourteen centuries, doesn’t explain all the political, economic, and geostrategic factors involved in these conflicts, but it has become one prism by which to understand the underlying tensions. Two countries that compete for the leadership of Islam, Sunni Saudi Arabia and Shia Iran, have used the sectarian divide to further their ambitions. How their rivalry is settled will likely shape the political balance between Sunnis and Shias and the future of the region, especially in Syria, Iraq, Lebanon, and Bahrain.

Alongside the proxy battle is the renewed fervor of armed militants, motivated by the goals of cleansing the faith or preparing the way for the return of the messiah. Today there are tens of thousands of organized sectarian militants throughout the region capable of triggering a broader conflict. And despite the efforts of many Sunni and Shia clerics to reduce tensions through dialogue and counterviolence measures, many experts express concern that Islam’s divide will lead to escalating violence and a growing threat to international peace and security.

Sunni and Shia Muslims have lived peacefully together for centuries. In many countries it has become common for members of the two sects to intermarry and pray at the same mosques. They share faith in the Quran and the Prophet Mohammed’s sayings and perform similar prayers, although they differ in rituals and interpretation of Islamic law.

Shia identity is rooted in victimhood over the killing of Husayn, the Prophet Mohammed’s grandson, in the seventh century, and a long history of marginalization by the Sunni majority. Islam’s dominant sect, which roughly 85 percent of the world’s 1.6 billion Muslims follow, viewed Shia Islam with suspicion, and extremist Sunnis have portrayed Shias as heretics and apostates.

Sunni Shia Muslim Population Graphic

Source: Pew Research, The Future of the Global Muslim Population, 2011

A regional war in the Middle East draws ever closer.

UN Independent International Commission of Inquiry on the Syrian Arab Republic

Origins of the Schism

Mohammed unveiled a new faith to the people of Mecca in 610. Known as Islam, or submission to God, the monotheistic religion incorporated some Jewish and Christian traditions and expanded with a set of laws that governed most aspects of life, including political authority. By the time of his death in 632, Mohammed had consolidated power in Arabia. His followers subsequently built an empire that would stretch from Central Asia to Spain less than a century after his death. But a debate over succession split the community, with some arguing that leadership should be awarded to qualified individuals and others insisting that the only legitimate ruler must come through Mohammed’s bloodline.

A group of prominent early followers of Islam elected Abu Bakr, a companion of Mohammed, to be the first caliph, or leader of the Islamic community, over the objections of those who favored Ali ibn Abi Talib, Mohammed’s cousin and son-in-law. The opposing camps in the succession debate eventually evolved into Islam’s two main sects. Shias, a term that stems from shi’atu Ali, Arabic for “partisans of Ali,” believe that Ali and his descendants are part of a divine order. Sunnis, meaning followers of the sunna, or “way” in Arabic, of Mohammed, are opposed to political succession based on Mohammed’s bloodline.

Ali became caliph in 656 and ruled only five years before he was assassinated. The caliphate, which was based in the Arabian Peninsula, passed to the Umayyad dynasty in Damascus and later the Abbasids in Baghdad. Shias rejected the authority of these rulers. In 680, soldiers of the second Umayyad caliph killed Ali’s son, Husayn, and many of his companions in Karbala, located in modern-day Iraq. Karbala became a defining moral story for Shias, and Sunni caliphs worried that the Shia Imams—the descendants of Husayn who were seen as the legitimate leaders of Muslims (Sunnis use the term “imam” for the men who lead prayers in mosques)—would use this massacre to capture public imagination and topple monarchs. This fear resulted in the further persecution and marginalization of Shias.

Even as Sunnis triumphed politically in the Muslim world, Shias continued to look to the Imams—the blood descendants of Ali and Husayn—as their legitimate political and religious leaders. Even within the Shia community, however, there arose differences over the proper line of succession. Mainstream Shias believe there were twelve Imams. Zaydi Shias, found mostly in Yemen, broke off from the majority Shia community at the fifth Imam, and sustained imamate rule in parts of Yemen up to the 1960s. Ismaili Shias, centered in South Asia but with important diaspora communities throughout the world, broke off at the seventh Imam. Ismailis revere the Aga Khan as the living representative of their Imam. The majority of Shias, particularly those in Iran and the eastern Arab world, believe that the twelfth Imam entered a state of occultation, or hiddenness, in 939 and that he will return at the end of time. Since then, “Twelvers,” or Ithna Ashari Shias, have vested religious authority in their senior clerical leaders, called ayatollahs (Arabic for “sign of God”).  

Many Christian, Jewish, and Zoroastrian converts to Islam chose to become Shia rather than Sunni in the early centuries of the religion as a protest against the ethnic Arab empires that treated non-Arabs as second-class citizens. Their religions influenced the evolution of Shia Islam as distinct from Sunni Islam in rituals and beliefs.    

Sunnis dominated the first nine centuries of Islamic rule (excluding the Shia Fatimid dynasty) until the Safavid dynasty was established in Persia in 1501. The Safavids made Shia Islam the state religion, and over the following two centuries they fought with the Ottomans, the seat of the Sunni caliphate. As these empires faded, their battles roughly settled the political borders of modern Iran and Turkey by the seventeenth century, and their legacies resulted in the current demographic distribution of Islam’s sects. Shias comprise a majority in Iran, Iraq, Azerbaijan, and Bahrain, and a plurality in Lebanon, while Sunnis make up the majority of more than forty countries from Morocco to Indonesia.

Timeline: Origins of the Sunni-Shia Schism

Early Muslims split into two camps following the death of the Prophet Mohammed. This chronology explains how the sects evolved from 632 until the late twentieth century. (Photo: Abbas Al-Musavi/Brooklyn Museum)

Combat between Ali ibn Abi Talib and Amr Ben Wad near Medina in Arabia.

The Death of Mohammed

Early followers of Islam are divided over the succession of the Prophet Mohammed, who founded the religion in Arabia. Prominent members of the community in Mecca elect Abu Bakr, a companion of Mohammed, with objections from those who favor Ali ibn Abi Talib, Mohammed’s cousin and son-in-law. Ali eventually becomes caliph, or ruler of the Islamic community, in 656, and is assassinated in 661 after a power struggle with the governor of Damascus, Mu’awiya. Mu’awiya claims the caliphate and founds the Umayyad dynasty, which rules the Muslim empire from Damascus until 750.

 

Painting of Ali being designated as the Prophet Mohammed’s successor.

The Early Shias

The partisans of Ali, or shi’atu Ali, grow discontented after the murder of their leader in 661. They reject the authority of the caliphs during the Umayyad dynasty, which rules over an expanding empire stretching from Pakistan through northern Africa to Spain. Shias argue that the legitimate leaders of Islam must be the sons of Ali and Fatima, Mohammed’s daughter. Husayn, one of Ali’s sons, eventually leads a revolt from Kufa, in modern-day Iraq.

Map of the Ummayad Caliphate in 750.

Umayyad and Abbasid Dynasties Target Shias

Umayyads, and later Abbasids, who replace the Umayyads and rule from Baghdad after 750, oppress and kill the successors of Husayn, known as Imams, who pose a political threat to Sunni caliphs. The sixth Shia Imam, Ja'far al-Sadiq, orders his followers to hide their true beliefs for the survival of the faith. Shia branches such as Ismaili and Zaydi emerge from different interpretations of succession for Imams. The Sunni caliphate becomes hereditary.  

Painting commemorating the martyrdom of Husayn.

The Battle of Karbala

Yazid, the Umayyad ruler, dispatches an army to crush the Kufa revolt. A battle in Karbala, north of Kufa, ends with the massacre of Husayn and many of his companions. Husayn's martyrdom and its moral lessons help shape Shia identity, and the sect grows despite the murder of its leaders. Husayn’s death is commemorated by Shias during the annual ritual of Ashura, which includes practices, such as self-flagellation, that are distinct from Sunni Islam.

Shia pilgrims gather at a shrine in Kerbala, Iraq. 

Occultation of the Mahdi

Most Shias today are Twelvers. They believe that the line of Imams continued to the twelfth Imam, Mohammed al-Mahdi, or the guided one, who entered a state of occultation, or hiddenness, in 939. Shias expect the Mahdi to return at the end of time. Sunni Islam becomes a broad umbrella term for non-Shia Muslims who are united on the importance of the Quran and practices of Mohammed, though they may differ in legal opinion.

Visitors at a shrine in Cairo believed to hold Husayn’s head. 

Fatimids: The First Shia Dynasty

Ismailis, who break off from the Twelver line after the sixth Imam, take control of Egypt and large parts of North Africa and expand to western Arabia and Syria, creating the Fatimid dynasty. The Fatimids, who assume the titles of both imam and caliph, establish al-Azhar Mosque, which centuries later becomes the intellectual center of Sunni Islam. The Shia Fatimid caliphate fades in the twelfth century, and the Ismaili community spreads to Yemen, Syria, Iran, and western India.

Ibn Taymiyya in Damascus

By the ninth century, Sunnis adhere to four schools of Islamic jurisprudence: Hanafi, Shafii, Maliki, and Hanbali. Ibn Taymiyya, a religious scholar, moves to Damascus in 1268 and studies the Hanbali school, which condemns Shias as rafidha, or rejecters of the faith. He preaches a return to the purity of Islam in its early days. Ibn Taymiyya opposes celebrating Mohammed’s birthday and other practices that resemble Christian and pagan rituals. His ideas help shape Wahhabi and Salafi thought centuries later. (Photo: Bernard Gagnon)

Painting of an early battle in the Safavid Dynasty by Mu'in Musavvir.

Safavid Dynasty and the Rise of Shias in Persia

Ismail, leader of the Safavid dynasty, defeats the Mongols and brings the territories of former Persian empires under central authority, including modern-day Iran, Iraq, Armenia, Georgia, Azerbaijan, and parts of Afghanistan, Pakistan, and Turkey. Shi’ism becomes the official religion of the Safavids and is often spread through force. As the Safavid dynasty declines in the eighteenth century, the power of Shia clergy in civil affairs grows in Iran.

Murad IV, Sultan of the Ottoman Empire from 1623 to 1640. (Public Domain/Wiki Commons)

Ottomans Conquer Iraq

Safavids briefly gain control of Iraq, an Arab territory, but lose it in 1639 to the Ottomans, who claim the title of the Sunni caliphate in Turkey. The Ottoman–Safavid wars eventually establish the modern contours of Turkey, Iraq, and Iran. Shia Islam dominates Iran, and Shia Muslims in Turkey are killed or displaced, shifting the demography in favor of Sunnis, a development that makes both these countries far more homogenous than their neighbors.

The renovated mosque of Mohammed ibn Abd al-Wahhab in Riyadh.

Wahhabi Islam Emerges in Arabia

Mohammed ibn Abd al-Wahhab establishes a religious movement on the Arabian peninsula in the eighteenth century steeped in the Hanbali school of Sunni Islam. Wahhabis, as his followers are known, preach a puritanical faith that puts them in conflict with other Sunnis as well as Shias. Wahhabi fighters desecrate the shrine of Husayn in Karbala and destroy Mohammed’s tombstone in Medina. They join Mohammed bin Saud to found the first Saudi kingdom, which is defeated by Ottoman forces in the early nineteenth century.

The Sykes-Picot Agreement.

Sykes–Picot and the End of the Caliphate

The secret Sykes-Picot agreement is reached between France and the United Kingdom to divide the Arab provinces of the Ottoman Empire, which has been in decline and weakens further during World War I. Colonial rulers elevate minorities to powerful positions in Iraq and Syria, a policy which later contributes to sectarian tensions in these countries. Tempering these tensions are new ideas of secularism and nationalism that sweep through the Turkish and Arab province of the former Ottoman Empire. The newly founded secular Republic of Turkey abolishes the caliphate in 1924. In the Arab world, identity politics stressing pan-Arabism and a unity among Muslims helps mute sectarianism, especially during the fight for independence against the European powers.

King Abdul Aziz Ibn Saud (seated) with his son, crown prince Saud.

Saud Dynasty Establishes a Kingdom

Abdul Aziz Ibn Saud and his army of Wahhabi warriors consolidate control of the Arabian peninsula and form the Kingdom of Saudi Arabia in 1932. During the founding battles, fighters attack fellow Sunnis in western Arabia and Shias in eastern Arabia and southern Iraq. Wahhabi preachers go on to dominate the kingdom’s judiciary and education system, and their teachings are spread first in Saudi Arabia and then internationally as the country grows wealthy from its large oil resources. The rise of Wahhabi and the related Salafi branches of Islam fuels Sunni-Shia tensions today.  

Mohammad Ali Jinnah

The Birth of Pakistan

India’s struggle for independence includes an Islamic awakening, resulting in the creation of Pakistan in the partition of India at the end of British rule. The Sunni-majority country is founded by a Shia, Mohammed Ali Jinnah, who emphasizes the need for a secular Pakistan where all citizens are equal irrespective of "religion or caste or creed." Pakistanis elect prime ministers from both sects. But the Islamization of the state, promoted by Saudi Wahhabi clerics, accelerates after army chief General Zia ul-Haq, a Sunni, seizes power in 1978. Sectarian violence escalates after the 1980s.

Al-Azhar Mosque in the old Islamic area of Cairo. 

Sectarian Harmony: The Azhar Fatwa

Sheikh Mahmoud Shaltut, the rector of Cairo's al-Azhar Mosque, which Sunnis view as the preeminent religious institution, issues a religious ruling, or fatwa, that recognizes Shia law as the fifth school of Islamic jurisprudence. After decades of colonialism and then secular nationalism, many Sunni and Shia religious authorities throughout the Muslim world unite to confront these common threats. This harmony is tarnished as secular states weaken.

Syrian president Hafez al-Assad in 1973.

Ba’ath Rule Begins in Syria

Syria’s first years of independence are riddled with coups until Ba’athists in the military seize power in 1963. The Ba’ath Party, popular in Iraq and Syria, promotes a secular, pan-Arab, socialist ideology and is hostile to Islamists. Hafez al-Assad, a Ba’ath leader and member of the heterodox Shia sect known as Alawis, takes power in 1970 and rules until his death in 2000, after more than a thousand years of Sunni dominance in Syria. His son Bashar continues to rule the country amid civil war in 2014.

Lebanese Civil War

Lebanon experiences a sectarian civil war that (with important exceptions at various times) pits the Christian minority that has held political power since independence in 1943 against the Muslim majority. Syria intervenes in the fighting in 1976 and Israel intervenes in 1982. After the Israeli intervention, Iran sponsors the establishment of a Shia Lebanese militia, Hezbollah, which over time becomes the most powerful force in Lebanese politics. Under pressure from Hezbollah, Israel withdraws its last forces from Lebanon in 2000. (Photo: AP)

Modern Tensions

Iran’s Islamic Revolution in 1979 gave Shia cleric Ayatollah Ruhollah Khomeini the opportunity to implement his vision for an Islamic government ruled by the “guardianship of the jurist” (velayat-e faqih), a controversial concept among Shia scholars that is opposed by Sunnis, who have historically differentiated between political leadership and religious scholarship. Shia ayatollahs have always been the guardians of the faith. Khomeini argued that clerics had to rule to properly perform their function: implementing Islam as God intended, through the mandate of the Shia Imams.

Under Khomeini, Iran began an experiment in Islamic rule. Khomeini tried to inspire further Islamic revival, preaching Muslim unity, but supported groups in Lebanon, Iraq, Afghanistan, Bahrain, and Pakistan that had specific Shia agendas. Sunni Islamists, such as the Muslim Brotherhood and Hamas, admired Khomeini’s success, but did not accept his leadership, underscoring the depth of sectarian suspicions.

Saudi Arabia has a sizable Shia minority of roughly 10 percent, and millions of adherents of a puritanical brand of Sunni Islam known as Wahhabism (an offshoot of the Sunni Hanbali school) that is antagonistic to Shia Islam. The transformation of Iran into an overtly Shia power after the Islamic revolution induced Saudi Arabia to accelerate the propagation of Wahhabism, as both countries revived a centuries-old sectarian rivalry over the true interpretation of Islam. Many of the groups responsible for sectarian violence that has occurred in the region and across the Muslim world since 1979 can be traced to Saudi and Iranian sources.

Saudi Arabia backed Iraq in the 1980–1988 war with Iran and sponsored militants in Pakistan and Afghanistan who were primarily fighting against the Soviet Union, which had invaded Afghanistan in 1979, but were also suppressing Shia movements inspired or backed by Iran.

The transformation of Iran into an agitator for Shia movements in Muslim countries seemed to confirm centuries of Sunni suspicions that Shia Arabs answer to Persia. Many experts, however, point out that Shias aren’t monolithic—for many of them, identities and interests are based on more than their confession. Iraqi Shias, for example, made up the bulk of the Iraqi army that fought Iran during the Iran–Iraq War, and Shia militant groups Amal and Hezbollah clashed at times during the Lebanese civil war.

Percent of Sunnis who accept Shias as Muslim Infographic

Source: Pew Research, The World’s Muslims: Unity and Diversity, 2012

For their part, both mainstream and hard-line Sunnis aren’t singularly focused on oppressing Shias. They have fought against coreligionists throughout history, most recently in the successive crackdowns on the Muslim Brotherhood in Egypt, Iraq’s 1990 invasion of Kuwait, and Saudi Arabia’s battles against al-Qaeda and related Sunni militant groups. Sharing a common Sunni identity didn’t eliminate power struggles among Sunni Muslims under secular or religious governments.

But confessional identity has resurfaced wherever sectarian violence has taken root, as in Iraq after the 2003 U.S.-led invasion removed Saddam Hussein, a dictator from the Sunni minority who ruled over a Shia-majority country. The bombing of a Shia shrine in Samara in 2006 kicked off a cycle of sectarian violence that forced Iraqis to pick sides, stirring tensions that continue today.

In the Arab world, Shia groups supported by Iran have recently won important political victories. The Assad regime, which has ruled Syria since 1970, relies on fellow Alawis, a heterodox Shia sect that makes up about 13 percent of Syria’s population, as a pillar of its rule. Alawis dominate the upper reaches of the military and security services in Syria and are the backbone of the forces fighting to support the regime of Bashar al-Assad in Syria’s civil war. Since the 2003 invasion of Iraq unseated Saddam Hussein and instituted competitive elections, the Shia majority has dominated the parliament and produced its prime ministers. Hezbollah, the Lebanese Shia militia and political movement, is the strongest political actor in Lebanon. Iran’s regional influence has swelled as its allies in these countries have accumulated power.

Sunni governments, especially Saudi Arabia, have increasingly worried about their own grips on power, a concern that was exacerbated with the protest movement that began in Tunisia in late 2010. The Arab Awakening, as the uprisings are known, spread to Bahrain and Syria, countries at the fault lines of Islam’s sectarian divide. In each, political power is held by a sectarian minority—Alawis in Syria, where Sunnis are the majority, and a Sunni ruling family in Bahrain, where Shias are the majority. The civil war in Syria, which is a political conflict at its core, has exposed sectarian tensions and become the staging ground for a vicious proxy war between the region’s major Sunni and Shia powers. Some analysts view the Syrian conflict as the last chance for Sunnis to limit and reverse the spread of Iranian power and Shia influence in the Arab world.

Timeline: Modern Sunni-Shia Tensions

Iran’s Islamic revolution, which brought Shias to power in 1979, and the Sunni backlash have fueled a competition for regional dominance. This timeline highlights Sunni-Shia tensions in recent decades. (Photo: Henri Bureau/Corbis)

Ayatollah Khomeini returns to Tehran in 1979 after fourteen years of exile. 

Iran’s Islamic Revolution

Iran’s ruler, Mohammad Reza Shah Pahlavi, flees the country after months of increasingly massive protests. Exiled Shia cleric Ayatollah Ruhollah Khomeini returns and leads an Islamic republic based on a constitution that grants him religious and political authority under the concept of velayat-e faqih (“guardianship of the jurist”). Khomeini is named supreme leader and starts to export the Islamic revolution, which is viewed with suspicion by Sunni rulers in countries with significant Shia populations, such as Iraq, Bahrain, Kuwait, the United Arab Emirates, Pakistan, Saudi Arabia, and Lebanon.

Soviet Army Invades Afghanistan

Soviet forces invade Afghanistan after the communist government in Kabul requests military aid to fight Islamist rebels. The insurgents, known as mujahadeen (“those who fight jihad”), attract mainly Afghan fighters and are augmented by thousands of foreign Sunni fighters, including a young Saudi named Osama bin Laden. Weapons and cash for the mujahadeen are supplied through Pakistan by Saudi Arabia and the United States. The war, which is framed as a resistance to Soviet occupation, raises the profile of fundamentalist Sunni movements.

Afghan tribal rebel with captured Soviet-made light machine gun.

Muhammad Zia Ul-Haq, Pakistan's sixth president,  ruled from 1978 to 1988. 

Shia Protests in Pakistan Exposes Sectarian Tensions

Tens of thousands of Shias protest in Islamabad against the imposition of some Sunni laws on all Muslims. Pakistan’s president gives Shias an exemption, but the sectarian confrontation becomes an important political issue in the country. Sunni groups such as Lashkar-e-Jhangvi and Sipah-e-Sahaba, funded by Wahhabi clerics in Saudi Arabia, kill thousands of Shias over the next three decades. Smaller Shia sectarian militant groups such as Tehrik-e-Jafria also emerge but are responsible for fewer attacks.

Iraq Sparks a War with Iran

Iraqi president Saddam Hussein, a Sunni ruling over a majority-Shia country who fears the spillover effects of the Iranian Revolution, sends his troops to occupy part of an oil-rich province in Iran. The move sparks an eight-year war, resulting in roughly one million deaths. Iraq is backed by Saudi Arabia and the United States, the latter responding to hostility from Tehran’s new government following the Islamic revolution and taking hostage of U.S. diplomats.

An Iraqi soldier watches the Iranian Abadan refinery burn during the Iran-Iraq conflict. 

Saddam Crushes Shia Insurgency After Gulf War

Riots erupt in the Shia cities of Basra and Najaf after U.S.-led allies drive Iraqi troops from Kuwait and rout them on the battlefield in the first Gulf War. The Shia protestors are in part motivated by a perception that they will receive U.S. backing if they turn against Saddam. U.S. officials say this was never promised. Saddam’s forces mount a brutal crackdown, killing tens of thousands of Shias, shelling the shrines of Najaf and Karbala, and razing parts of Shia towns.

Bodies suspected to be Shias killed by Saddam’s regime are found in a mass grave in 2003. 

Taliban Massacres Shia in Mazar-e-Sharif

Taliban militants, Sunni fundamentalists who seized power after the defeat of Soviet forces, capture the city of Mazar-e-Sharif in northwest Afghanistan. The Taliban kills at least two thousand Shias in Mazar-e-Sharif and Bamiyan in 1997 and 1998. The offensive in northwest Afghanistan, backed by Pakistan, helps the Taliban consolidate power in the country. Militants kill eight Iranian diplomats based in Mazar-e-Sharif, prompting Tehran to deploy its troops to the border, but United Nations mediation averts a confrontation.

Afghans flock to the Blue Mosque, also known as the Tomb of Ali, in Mazar-e-Sharif. (Courtesy Reuters)

The second tower of the World Trade Center explodes into flames on September 11, 2001. 

Al-Qaeda Strikes the U.S., Killing Thousands

In response to the attacks on New York and Washington, U.S. forces pursue al-Qaeda leaders and militants to their bases in Afghanistan and overthrow the Taliban government. U.S.-led international troops help set up a new order in the country. The toppling of the anti-Iranian Taliban government in Afghanistan, followed shortly thereafter by the U.S. invasion of Iraq that brings down another Iranian foe, Saddam Hussein, fans Sunni fears in Jordan and Gulf states of a Shia revival.

U.S. troops pull down a twenty-foot statue of Saddam Hussein in central Baghdad. 

U.S. Forces Topple Saddam Hussein in Iraq

A coalition led by the United States invades Iraq and ends Saddam’s regime and centuries of Sunni dominance in Iraq. Sectarian violence erupts as remnants of the deposed Ba’ath party and other Sunnis, both secular and Islamist, mount a resistance against coalition forces and their local allies, the ascendant Shia community.  Shia militias also emerge, some of which also oppose the U.S. military presence. Foreign Sunni militants, many affiliated with al-Qaeda, flock to Iraq to participate in what evolves into a sectarian war. Iranian influence in Iraq grows dramatically as Tehran backs Shia militants, as well as the Shia political parties that come to dominate the electoral process.

Supporters of Rafik Hariri in protest over his killing.

Assassination of Former Lebanese Prime Minister Rafik Hariri

Former Lebanese prime minister Rafik Hariri is killed in a car bomb after spearheading an effort to raise international pressure on Syria to withdraw its forces, which have been in Lebanon since 1976. His assassination is seen as a Syrian plot supported by Syria’s Lebanese allies, including Hezbollah, and leads to massive demonstrations that convince Syria to withdraw. The assassination and subsequent mobilization pit the Lebanese Sunni community, whom Hariri had come to represent, against Hezbollah and Lebanese Shias, who remain allied with Syria. Lebanese Christians split, with some supporting the Hariri camp and others supporting Hezbollah.

Iraqis walk past the damaged al-Askari mosque following an explosion in Samarra. 

Bombing of Shia Shrine Escalates Iraq Violence

Sectarian killings become normal in Iraq, with both Sunni and Shia militias targeting civilians across the country. The bombing that destroys the golden dome of al-Askari mosque in Samarra, home to the tombs of the tenth and eleventh Shia Imams, triggers a more intense wave of violence that almost doubles the monthly civilian death toll in Iraq to nine hundred.

Indian Muslims protest the execution of Saddam Hussein.

Saddam’s Execution Inflames Sunnis

Saddam Hussein, responsible for the deaths of thousands of Shias and Sunnis in Iraq, is executed amid taunts by witnesses who chant the name of Shia cleric and Mahdi army militia leader Muqtada al-Sadr. The unruly scene, captured on video, elevates Saddam’s status as a martyr among many Sunnis in the region and underscores the new reality of rising Shia power in Iraq.

Protests Erupt in the Middle East, Exposing Sectarian Fault Lines

A wave of pro-democracy protests sweeps across the region, starting with the overthrow of Tunisia’s president, and then Egypt’s on February 11, eventually spreading to other Arab states in what is known as the “Arab Spring” or the “Arab Awakening.” Iranian officials welcome the fall of long-term U.S. allies like Egypt’s president, Hosni Mubarak, and unrest in Bahrain, home to an oppressed Shia majority. As protests reach Syria in March, Tehran backs the government, which is dominated by Alawis, a heterodox Shia sect, while the opposition is dominated by members of the majority Sunni community. Dormant sectarian tensions in Syria are revived and a regional sectarian showdown begins.  (Courtesy Reuters)

Iranian president Mahmoud Ahmadinejad talks to Egypt's president, Mohammed Morsi, during the sixteenth summit of the Nonaligned Movement in Tehran. 

Egypt’s Morsi Visits Iran

President Mohamed Morsi’s trip to Tehran, the first visit by an Egyptian leader since Cairo’s recognition of Israel in the 1980s, signals the potential for a new relationship between Iran and Sunni Islamists. Iran tries to rebrand the Arab uprisings as an “Islamic Awakening”  and an extension of the Islamic Revolution of 1979. But the visit by Morsi, of the Muslim Brotherhood, exposes Islam’s deep cleavage. He praises Islam’s first three caliphs, whom Shias reject, and says opposing the Assad regime is a “moral obligation,” remarks that Iranian officials criticize.

Hezbollah members carry the coffin of commander Ali Bazzi, who was killed in Syria. 

Hezbollah Commander Killed in Syria

Civil war divides Syrians largely along sectarian lines, with Sunnis supporting rebels, and Alawis, Shias, and other minorities backing the Assad regime. Foreign Sunni fighters trickle and then flood into the country, and signs of increased involvement from Iran and its Lebanese proxy militia, Hezbollah, emerge. The death of Hezbollah founding member Ali Hussein Nassif comes months before the group publicly acknowledges its role in the war. Saudi Arabia and other Gulf countries fund rebels, turning the fighting in Syria into a regional proxy war.

Al-Qaeda’s Iraq Affiliate Expands in Syria

The Islamic State of Iraq, al-Qaeda’s affiliate in the country, extends its activities into Syria, creating the Islamic State of Iraq and Syria (ISIS). Known for its brutality against Shias and most Sunnis who oppose it, the group proves to be too extreme for al-Qaeda and is eventually expelled from the network. ISIS attacks in Iraq and Syria add an additional layer of sectarian violence to the region, and its control of territory in both states threatens to dissolve borders and fracture countries in the Middle East. (Yaser Al-Khodor/Courtesy Reuters)

Indonesian Shias protest plans to relocate hundreds who had been driven from their village.

Anti-Shia Sentiments Spread to Indonesia

Asian Muslims, influenced by the sectarian violence in the Middle East and Pakistan, aim to avoid potential tensions by suppressing the growth of their tiny Shia communities. Indonesian clerics and radical Islamists hold an “Anti-Shia Alliance” meeting in the world’s largest Muslim country, which is more than 99 percent Sunni. Malaysia, where Sunnis are also dominant, has implemented laws forbidding the propagation of the Shia faith.

Mahdi Army fighters loyal to Shia cleric Muqtada al-Sadr march in Najaf. 

Shia Militias Mobilize as ISIS Advances in Iraq

ISIS militants and other armed Sunni groups seize Mosul, Iraq’s second-largest city, with little resistance from the Iraqi army. The Sunni insurgency, brewing for years in response to what it sees as exclusionary policies of Shia prime minister Nouri al-Maliki, expands toward Baghdad and the borders with Syria and Jordan. ISIS threatens to destroy sacred Shia shrines, prompting a call to arms by Iraq’s top Shia cleric, Grand Ayatollah Ali al-Sistani. Shia civilians respond to a mass recruitment drive that swells the ranks of militias and elevates sectarian tensions.

Practicing the Faith

Sunnis and Shias agree on the basic tenets of Islam: declaring faith in a monotheistic God and Mohammed as his messenger, conducting daily prayers, giving money to the poor, fasting during the Muslim holy month of Ramadan, and performing the pilgrimage to Mecca.

There are divisions even over the precepts of Islam, but the main difference relates to authority, which sparked the political split in the seventh century and evolved into divergent interpretations of sharia, or Islamic law, and distinct sectarian identities.

Shias believe that God always provides a guide, first the Imams and then ayatollahs, or experienced Shia scholars who have wide interpretative authority and are sought as a source of emulation. The term “ayatollah” is associated with the clerical rulers in Tehran, but it’s primarily a title for a distinguished religious leader known as a marja, or source of emulation. Iran’s supreme leader, Ali Khamenei, was appointed by an elected body of Iranian clerics, while maraji (plural of marja) are elevated through the religious schools in Qom, Najaf, and Karbala. Shias can choose from dozens of maraji, most of whom are based in holy cities in Iraq and Iran. Many Shias emulate a marja for religious affairs and defer to Supreme Leader Ali Khamenei in Iran for political guidance. For Sunnis, authority is based on the Quran and the traditions of Mohammed. Sunni religious scholars, who are constrained by legal precedents, exert far less authority over their followers than their Shia counterparts.

Both sects have subdivisions. The divisions among Shias were discussed above. Four schools comprise Sunni jurisprudence: Hanafi, Shafii, Maliki, and Hanbali, the latter spawning the Wahhabi and Salafi movements in Saudi Arabia. Sunnism, a broad umbrella term for non-Shia Islam, is united on the importance of the Quran and practice of Mohammed but allows for differences in legal opinion.

Dear Karbala, dear Najaf, dear Kadhimiyah, and dear Samarra, we warn the great powers and their lackeys and the terrorists, the great Iranian people will do everything to protect them.

Iranian president Hassan Rouhani

Sectarian Militants

Communal violence between Islam’s sects has been rare historically, with most of the deadly sectarian attacks directed by clerics or political leaders. Extremist groups, many of which are fostered by states, are the chief actors in sectarian killings today.

The two most prominent terrorist groups, Sunni al-Qaeda and Shia Hezbollah, have not defined their movements in sectarian terms, and have favored using anti-imperialist, anti-Zionist, and anti-American frameworks to define their jihad, or struggle. They share few similarities beyond the use of violence. Hezbollah has developed a pragmatic political wing that competes in elections and is part of the Lebanese government, a path not chosen by al-Qaeda, which operates a diffuse network largely in the shadows. Both groups have deployed suicide bombers, and their attacks shifted from a focus on the West and Israel to other Muslims, such as al-Qaeda’s killing of Shia civilians in Iraq and Hezbollah’s participation in the Syrian civil war.

Conflict and chaos have played a role in the reversion to basic sectarian identity. In Iraq, for instance, remnants of the Ba’athist regime employed Sunni rhetoric to mount a resistance to the rise of Shia power following the ouster of Saddam. Sunni fundamentalists, many inspired by al-Qaeda’s call to fight Americans, flocked to Iraq from Muslim countries, attacking coalition forces and many Shia civilians. Abu Musab al-Zarqawi, who founded al-Qaeda’s franchise in Iraq, evoked ancient anti-Shia fatwas, or religious rulings, to spark a civil war in hopes that the Shia majority would eventually capitulate in the face of Sunni extremist violence. The Shia community absorbed thousands of deaths before fighting back with their own sectarian militias.

Syria’s civil war, which exceeded the brutality and casualty toll of Iraq’s decade-long conflict in just three years, has amplified sectarian tensions to unprecedented levels. The war began with peaceful protests in 2011 calling for an end to the Assad regime, which has ruled since 1970. The Assad family and other Alawis have stirred resentment by Syria’s majority Sunnis after decades of brutal repression and a sectarian agenda that elevated minority Alawis in government and the private sector. The 2011 protests and brutal government crackdown uncovered sectarian tensions in Syria, which have rippled across the region.

Tens of thousands of Syrian Sunnis joined rebel groups such as Ahrar al-Sham, the Islamic Front, and al-Qaeda’s Nusra Front, which all employ anti-Shia rhetoric; similar numbers of Syrian Shias and Alawis enlisted with an Iran-backed militia known as the National Defense Force to fight for the Assad regime. Foreign Sunni fighters from Arab and Western countries joined the rebels, while Lebanon’s Hezbollah and some Shia militias from Iraq such as Asaib Ahl al-Haq and Kata'ib Hezbollah backed the Syrian government. Even Afghan Shia refugees in Iran have reportedly been recruited by Tehran for the war in Syria, pitting them against Sunni foreign fighters who may have forced the Afghans into exile decades earlier. Syria’s civil war has attracted more militants from more countries than were involved in the conflicts in Afghanistan, Chechnya, and Bosnia combined.

Al-Qaeda in Iraq, decimated by the “Awakening” of Sunni Iraqis who joined the fight against extremists, the U.S.-led military surge, and the death of Zarqawi, found new purpose in exploiting the vacuum left by the receding Syrian state. It established its own transnational movement known as the Islamic State in Iraq and Syria (ISIS). The group expanded its grip on Sunni provinces in Iraq and eastern regions in Syria, seizing Iraq’s second-largest city, Mosul, in June 2014. It defied orders from al-Qaeda’s top commanders to curtail its transnational ambitions and extremism, which led to ISIS’s expulsion from al-Qaeda in February 2014. ISIS rebranded as the Islamic State in July 2014 and declared its leader, Abu Bakr al-Baghdadi, as caliph.

Extremist groups have come to rely on satellite television and high-speed Internet over the past two decades to spread hate speech and rally support. Fundamentalist Sunni clerics, many sponsored by wealthy Sunnis from Saudi Arabia and the Gulf states, have popularized anti-Shia slurs. Shia religious scholars have also taken to the airwaves, mocking and cursing the first three caliphs and Aisha, one of Mohammed’s wives.

Sectarian rhetoric dehumanizing the “other” is centuries old. But the volume is increasing. Dismissing Arab Shias as Safawis, a term that paints them as Iranian agents (from the Safavid empire) and hence traitors to the Arab cause, is increasingly common in Sunni rhetoric. Hard-line Sunni Islamists have used harsher historic terms such as rafidha, rejecters of the faith, and majus, Zoroastrian or crypto Persian, to describe Shias. Iranian officials, Iraq’s prime minister, and Hassan Nasrallah, the leader of Hezbollah, routinely describe their Sunni opponents as takfiris (code for al-Qaeda terrorists) and Wahhabis. This cycle of demonization has been exacerbated throughout the Muslim world.

For Sunni extremists, new technologies and social-media channels have revolutionized recruitment opportunities. Fundamentalists no longer have to infiltrate mainstream mosques and attract recruits surreptitiously, but can now disseminate their call to jihad and wait for potential recruits to contact them. These channels aren’t as useful for recruiting Shia militants, who benefit from state support in Syria, Iraq, and Iran, and can openly advertise their calls for sectarian jihad.

The Sunni-Shia Divide

Terrorist violence in 2013 was fueled by sectarian motivations, marking a worrisome trend, in particular in Syria, Lebanon, and Pakistan.

U.S. Department of State

Flash Points

Sunni-Shia tensions contribute to multiple flash points in Muslim countries that are viewed as growing threats to international peace and security. The following arouse the most concern among regional specialists:

Rising Militancy

Notable concern about the role of sectarian violence increased in 2013. Extremists were “fueled by sectarian motivations” in Syria, Lebanon, and Pakistan, according to the U.S. State Department. After years of steady losses for al-Qaeda–linked groups, Sunni extremist recruitment is rising, aided by private funding networks in the Gulf, particularly in Kuwait, with much of the violence directed at other Muslims rather than Western targets. Shia militants are also gaining strength, in part to confront the threat of Sunni extremism, miring many Muslim communities in a vicious cycle of sectarian violence.

U.S. officials such as FBI director James B. Comey have warned that the war in Syria, which attracted thousands of fighters from Europe and the United States, poses a long-term threat to Western interests. The eventual outflow of these militants, battle-hardened and with Western passports, is viewed as a potential “terrorist diaspora” that could eclipse the global terror networks that emerged after the Afghan war against the Soviet Union in the 1980s.

Saudi-Iranian Rivalry

Saudi Arabia and Iran have deployed considerable resources to proxy battles, especially in Syria, where the stakes are highest. Riyadh closely monitors potential restlessness in its oil-rich eastern provinces, home to its Shia minority, and has deployed forces along with other Gulf countries to suppress a largely Shia uprising in Bahrain. Saudi Arabia is also providing hundreds of millions of dollars in financial support to the predominantly Sunni rebels in Syria, while simultaneously banning cash flows to al-Qaeda and extremist jihadi groups fighting the Assad regime.

Iran has allocated billions of dollars in aid and loans to prop up Syria’s Alawi-led government, and has trained and equipped Shia militants from Lebanon, Iraq, Syria, and Afghanistan to fight with various sectarian militias in Syria. At the same time, the widening proxy battle may also be stirring concern among leaders in Riyadh and Tehran about the consequences of escalation. The two sides were reported to be in talks in May 2014 to establish a dialogue for settling disputes diplomatically.

Humanitarian Crisis

The ongoing civil war in Syria has displaced millions internally, and almost three million civilians, mostly Sunni, are now refugees in Lebanon, Jordan, Iraq, and Turkey. The influx of more than a million Syrians into Lebanon, a state with a historically combustible religious mix that experienced its own fifteen-year civil war in the 1970s and 1980s, has burdened its cash-strapped government and pressured communities hosting refugees. Jordan and Iraq are still struggling to provide housing and services to an impoverished and traumatized population. Turkey has the greatest capacity to provide humanitarian aid, yet Ankara must increasingly balance “the public’s sympathy for and unease toward refugees,” the International Crisis Group reports.

Fractured States

Syria’s civil war, as well as Iraq’s sectarian conflict, is threatening to redraw the map of the Middle East bequeathed to the region by British and French colonial authorities. The Assad regime in Syria has consolidated control over the Mediterranean coast, the capital of Damascus, and the central city of Homs, which together comprise a rump state that connects with Hezbollah strongholds, threatening the territorial integrity of Lebanon. Other parts of the country are contested or controlled by various rebel and Islamist groups, including ISIS, which seeks to dominate the eastern regions of Syria that link to its territory in Iraq. And Kurdish groups in northern Syria, which, like their Iraqi cousins, have long campaigned for basic rights denied under the Ba'athist government, are on the verge of gaining de facto independence.

The United States spent more than one trillion dollars to stabilize Iraq, but the country remains in a precarious state. Sectarian tensions are mounting in Iraq as the newly ascendant Shia majority struggles to accommodate the Sunni minority and deal with the Kurdish Regional Government in the north of the country while confronting extremist Sunni groups. Most politicians and activists in Iraq, Syria, and Lebanon reject attempts to redraw the map of the region, but the vanishing borders and emergence of new areas of influence based on sectarian and ethnic identities are a growing existential challenge.

Sunnis had no other option but to defend themselves and use arms. We reached a point of to be or not to be.

Tariq al-Hashimi, former vice president of Iraq

Resources

experts

Geneive Abdo

Fellow, Middle East Program, Stimson Center

Deborah Amos

Middle East Correspondent, National Public Radio

Reza Aslan

Associate Professor, University of California, Riverside

F. Gregory Gause III

Senior Fellow, Brookings Doha Center

Bruce Hoffman

Director, Center for Security Studies, Georgetown University

Ed Husain

Adjunct Senior Fellow for Middle Eastern Studies, CFR

Vali R. Nasr

Dean, School of Advanced International Studies, Johns Hopkins University

further-reading

Current Tensions

The Roots and Future of Sectarianism in the Gulf (March 2014)

Frederic Wehrey of the Carnegie Endowment explains the limits of analyzing conflicts solely through the Sunni-Shia prism, with a focus on sectarianism in the Gulf.

Iran’s Foreign Minister Snubs a Saudi Invite (June 2014)

Brookings senior fellow Suzanne Maloney explores Iran-Saudi relations.

Saudi Arabia’s Hidden Uprising (May 2014)

Saudi Arabia has largely suppressed a Shia uprising in the kingdom, according to this BBC report.

Syria’s Uprising Within an Uprising (January 2014)

Sunni rebels in Syria are fighting against their coreligionists from ISIS, complicating the sectarian fault lines of Syria’s civil war, explains Rania Abouzeid of the European Council on Foreign Relations.

Rise of Sunni Foreign Fighters in Syria (December 2013)

Foreign fighters in Syria, especially Sunnis with Western passports, are a looming risk for many countries. Aaron Zelin of the Washington Institute for Near East Policy tracks the rise of foreign Sunni fighters.

Iran-backed Shia Militias Flock to Syria (March 2014)

The Guardian reports on the involvement of Iraqi Shia militias in Syria’s war.

Bahrain’s Fake Sectarian War (June 2013)

Reza Aslan explains in this 2013 Foreign Affairs essay how Bahrain exploited the kingdom’s sectarian divide to discredit a nonsectarian uprising for greater political freedom.

The New Sectarianism (April 2013)

Geneive Abdo of the Brookings Institution uses Lebanon and Bahrain as case studies to explore heightened Sunni-Shia tensions following the “Arab Awakening” protests of 2011.

Iraq’s Sunnis and the State (August 2013)

Iraq’s Sunnis have grown frustrated with the political process, and the Shia government’s crackdown on peaceful protests have rekindled a Sunni insurgency, the International Crisis Group explains in this 2013 report.

General/Overview

Islam: Sunni and Shiites (January 2009)

The nonpartisan Congressional Research Service reviews the basics of the Sunni-Shia divide.

When the Shiites Rise (July 2006)

Vali Nasr explains how the toppling of Saddam Hussein in Iraq helped launch a Shia revival in the country and the Middle East in this Foreign Affairs article. Nasr expands on the roots of the Sunni-Shia divide in his 2007 book "The Shia Revival: How Conflicts within Islam Will Shape the Future."

Across the Arab World, a Widening Rift (February 2007)

Evidence of simmering sectarian tensions is examined in this sweeping report on the region by the late Middle East correspondent Anthony Shadid.

The Partisans of Ali (February 2007)

This five-part NPR series explores the Sunni-Shia divide.

Mapping the Global Muslim Population (October 2009)

This demographic study by Pew Research maps the global Muslim population. Pew also studies Sunni and Shia attitudes, and its 2012 poll shows that many Muslims worry about religious conflict.

Can You Tell a Sunni from a Shiite? (October 2006)

Many U.S. counterterrorism officials struggle to explain the differences between Sunnis and Shias in this New York Times article.

Sectarian Militants

Apocalyptic Prophecies Motivate Shia and Sunni Fighters (April 2014)

Shia and Sunni fighters around the world use end-times prophecies to justify their involvement in the wars in Iraq and Syria, Mariam Karouny of Reuters reports.

Lebanon’s Hezbollah Turns Toward Syria (May 2014)

The International Crisis Group examines Hezbollah’s involvement in the Syrian civil war.

Iraqi Fighters in Syria’s Shia Militias (August 2013)

This CTC Sentinel article explores the regional expansion of Iraqi Shia militias into Syria.

Iran’s Shadow Commander (September 2013)

The New Yorker’s Dexter Filkins profiles Qassem Suleimani, an Iranian commander in charge of his country’s proxy war efforts in Iraq and Syria.

Al-Qaeda: A Persistent Threat (2014)

The RAND Corporation tracks the evolution of al-Qaeda and other Salafi groups and assesses the threats posed by various affiliates.

The ISIS Battle Plan (June 2014)

The Institute for the Study of War examines ISIS battle plans in Iraq. The Washington-based think tank has published many reports on ISIS and monitors the group's evolution in Iraq and Syria.

educational-resources

These discussion questions, essay questions, activities and assignments, and supplementary resources are designed to help educators use “The Sunni-Shia Divide” InfoGuide in the classroom through an active, learner-centered approach.

Discussion Questions

Ideas for questions to use in facilitating full-class discussions, assigning small group discussion topics, or posting on a class discussion board. Questions allow students to critically reflect on the material provided in the InfoGuide and hone their communication skills.

Essay Questions

Suggestions for essay topics that enable students to dive deeper into the material found in the InfoGuide and conduct their own research and analysis.

Activities and Assignments

In-class activity ideas and homework assignments based on “The Sunni-Shia Divide” that promote participatory learning and critical thinking. These can be adapted based on students’ levels and classroom needs. For high school teachers, these activities are accompanied by a list and description of the Common Core State Standards they meet.