Al-Qaeda in Iraq (AQI), a jihadist group of predominantly Sunni fighters, rose to prominence in the ashes of the U.S.-led invasion to oust Saddam Hussein. The insurgency that followed provided the group with fertile ground to wage a guerrilla war against coalition forces and their domestic supporters. In the face of successful U.S. counterterrorism efforts and the Sunni tribal awakening, AQI's campaign of violence has diminished since peak years of 2006 and 2007, but the group remains a threat to stability in Iraq and the broader Levant.
Since the complete withdrawal of U.S. forces in late 2011, AQI has accelerated the pace of attacks on mainly Shiite targets in what analysts say is an attempt to reignite conflict between Iraq's Sunni minority and the Shiite-led government of Nuri al-Maliki. A surge in violence in mid-2013 has resulted in some eight hundred civilian deaths per month, according to the United Nations. Meanwhile, the militant group has expanded its reach into neighboring Syria, rebranding itself as the Islamic State of Iraq and Greater Syria (a.k.a. Islamic State of Iraq and the Levant), as its jihadists challenge both the Assad regime and other opposition groups.
Al-Qaeda in Iraq, also known as the Islamic State in Iraq and Greater Syria (ISIS) is a Sunni Muslim extremist group that seeks to sow civil unrest in Iraq and the Levant, with the aim of establishing a caliphate—a single, transnational Islamic state based on sharia law. Established by Abu Musab al-Zarqawi, an Arab of Jordanian descent, AQI rose to prominence after the U.S.-led invasion of Iraq in 2003. Zarqawi, after being released from a Jordanian prison in 1999, commanded volunteers in Herat, Afghanistan, before fleeing to northern Iraq in 2001. There he joined with Ansar al-Islam (Partisans of Islam), a militant Kurdish separatist movement, where he led the group's Arab contingent. Many analysts say this group, not al-Qaeda, was the precursor to AQI.
Ahead of the 2003 invasion, U.S. officials made a case before the UN Security Council linking AQI with Osama bin Laden. But a number of experts say it wasn't until October 2004, when Zarqawi officially vowed obedience to the al-Qaeda leader, that the groups became linked. The U.S. State Department designated AQI a Foreign Terrorist Organization that same month. "For al-Qaeda, attaching its name to Zarqawi's activities enabled it to maintain relevance even as its core forces were destroyed [in Afghanistan] or on the run," observed Brian Fishman, a counterterrorism fellow at the New America Foundation.
According to a 2011 report by the Center for Strategic and International Studies, Zarqawi had prepared carefully for the invasion, developing a four-pronged strategy [PDF] to defeat the coalition: isolate U.S. forces by targeting its allies; discourage Iraqi collaboration by targeting government infrastructure and personnel; target reconstruction efforts through high-profile attacks on civilian contractors and aid workers; and draw the U.S. military into a Sunni-Shiite civil war by targeting Shiites.
Two decisions made by the Coalition Provisional Authority (CPA)—the transitional government established by the United States and its coalition partners—early in the U.S.-led occupation are often cited by some critics as factors that helped feed the insurgency and provide breeding ground for AQI and several other Sunni extremist groups in Iraq. CPA order number one banned members of Saddam Hussein's Ba'ath party from all government positions; number two disbanded the Iraqi army and security services, creating hundreds of thousands of new coalition enemies, many of them armed.
In July 2005, bin Laden and his number two at the time, Ayman al-Zawahiri, believed AQI's increasingly sectarian attacks on Shiites would erode public support for al-Qaeda in the region, and questioned Zarqawi's strategy in written correspondence. Fishman says the relationship eventually broke down when Zarqawi ignored al-Qaeda instructions to stop attacking Shiite cultural sites. However tenuous the relationship between the al-Qaeda core and its Iraq affiliate, it ended in June 2006, when a U.S. air strike killed the AQI founder. The hit marked a major victory for U.S. and Iraqi intelligence, and a turning point for the organization.
In the aftermath, Abu Ayyub al-Masri, an Egyptian-born explosives expert and former confidant of al-Qaeda deputy Zawahiri, emerged as the group's new leader. In October 2006, Masri established the Islamic State of Iraq to increase the terrorist's group local appeal and embody its "caliphate," or political arm. An Iraq native, Abu Omar al-Baghdadi, was placed at ISIS's helm. For a while, U.S. officials believed Masri and Baghdadi might be the same person, but in April 2010 the White House ended the confusion, announcing that an Iraqi-led operation killed both men near Tikrit.
AQI is currently led by Abu Bakr al-Baghdadi. The U.S. government believes Abu D'ua, as he is known, resides in Syria, highlighting the extent to which AQI has exploited opportunities beyond Iraq's borders.
Experts say supporters in the region, including those based in Jordan, Syria, and Saudi Arabia, provided the bulk of past funding. Prior to his death, a great deal of operational funding was provided by Zarqawi's support network. AQI has also received financing from Tehran (despite the fact that al-Qaeda is a Sunni organization), according to documents confiscated in 2006 from Iranian Revolutionary Guards operatives in northern Iraq.
But the bulk of al-Qaeda's financing, experts say, comes from internal sources like smuggling, extortion, and other crime. AQI has relied in recent years on funding and manpower from internal recruits [PDF]. In Mosul, an important AQI stronghold, the group extorts taxes from businesses small and large, netting upwards of $8 million a month, according to some estimates.
The makeup of AQI has evolved greatly over the years, transitioning from a group with a significant ratio of foreign fighters--many drawn initially from Zarqawi's networks (PDF) in Pakistan and Afghanistan, and later merged with recruits from Syria, Iraq, and its neighbors--to a group dominated by native Iraqis. The Washington Post reported that 2006 marked a year of "dramatic changes" in AQI membership, shifting it from a predominantly foreign force to an "overwhelmingly Iraqi organization."
Experts note that it's difficult to assess AQI's size, and approximations have fluctuated greatly over the years. Terrorism analysts estimated some 15,000 fighters before numbers dropped off precipitously with the onset of the Sunni tribal backlash in 2006 and the U.S. troop surge of 2007. According to CSIS, more than 11,000 AQI fighters were killed or captured by early 2008.
As the Pentagon prepared to withdraw its final contingent of troops in late 2011, defense officials estimated AQI had some 800 to 1,000 fighters remaining. However, less than a year later, Iraqi officials said AQI ranks doubled to some 2,500, noting that counterterrorism operations "had been negatively affected by the U.S. pullout."
Many analysts say heavy-handed actions taken by the Maliki government to consolidate power in the wake of the U.S. withdrawal have alienated much of the Sunni minority and provided AQI with potent propaganda. In 2012 and 2013, violence attributed to AQI intensified, highlighting the group's attempts to exploit widening sectarian cleavages. According to a report by the Congressional Research Service [PDF], there were roughly a dozen days in 2012 on which the group executed multi-city attacks that killed at least twenty-five Iraqis. On at least four of those days, coordinated attacks left more than a hundred Iraqis dead.
Since Sunni protests in Anbar and other provinces began in December 2012, car bombings and suicide attacks intensified, with coordinated attacks regularly targeting Shiite markets, cafes, and mosques. Over six thousand civilians were killed between November 2012 and September 2013, the United Nations estimates, with Baghdad bearing the brunt of violence. Meanwhile, most Sunnis have denounced the bloodshed.
In July, ISIS fighters orchestrated bold attacks on two prisons outside Baghdad (Abu Ghraib and Taji) that freed more than five hundred inmates, including top al-Qaeda militants. Interpol described the incidents as "a major threat to global security." In August, the International Crisis Group warned that the country verged on civil war.
Meanwhile, the civil war in neighboring Syria is drawing Sunni jihadist fighters to join the rebellion against the regime of Bashar al-Assad, which is dominated by the Alawite sect, a minority Shiite group. ISIS has been active in Syria's northern and eastern provinces, where it has taken administrative control of some towns, providing services while imposing its ultraconservative brand of Islamic law.
While al-Qaeda–linked groups in Syria have feuded among themselves and with the secular opposition, the Free Syrian Army signed a truce with ISIS in late September, an acknowledgment of their efficacy on the battlefield.
Washington has responded to al-Qaeda's resurgence in the region by increasing the CIA's support for the Maliki government, including assistance to elite counterterrorism units that report directly to the prime minister. At the same time, the significant jihadist spillover into Syria has given the Obama administration pause as it moves to provide limited arms to the rebellion against Assad. Briefing the UN Security Council in July 2013, UN envoy to Iraq Martin Kobler characterized the spiraling regional dynamics: "[Iraq and Syria] are interrelated. Iraq is the fault line between the Sunni and Shia worlds."