Born out of the anti-Soviet jihad in Afghanistan during the Cold War, Al-Qaeda would grow over the ensuing decades to become one of the most prolific and consequential global terror groups to ever exist. Its mission – to form a global movement of Islamic sharia governance rooted in Wahhabi and Ikhwani religious philosophies and to wage war against the United States and its allies – has taken the organization to South and Central Asia, North and Sub-Saharan Africa, North America, the South Pacific, and Europe. The organization has killed thousands of people, and instigated a now-decades old war with the events of September 11, 2001.
In contrast to its ideological progeny and current rival, the Islamic State (IS), Al-Qaeda tries to blend in with the societies it eventually seeks to co-opt. This has led to the formation of several satellite organizations, each of which operate at various capacities and different capabilities. After a period of relative inactivity on the global jihad stage, Al-Qaeda now appears to be reemerging. The 2020 assassination of U.S. Navy servicemembers in Pensacola, Florida, the fall of the Islamic State’s physical caliphate in Iraq and Syria, and continued activity by the organization in both Afghanistan and North Africa all signal the group’s continued viability, as well as its ongoing desire to reclaim the mantle of the world’s preeminent Islamist extremist organization.
NOVEMBER 2021 UPDATE
Al-Qaeda remains a viable movement with global reach, as incidents throughout Africa and Asia in 2020 and 2021 have made clear. With the Taliban’s August takeover of Afghanistan, worries have abounded that al-Qaeda could once again find a safe haven in that country in the near future. For its part, the United States continues to work to erode al-Qaeda’s capabilities, including through the targeting of the organization’s leadership (such as the killing by drone strike of a senior leader in Syria in late October 2021).
History & Ideology
Though the attacks of September 11, 2001 are the most profound symbol of al-Qaeda’s notoriety, the group finds its roots in another, more conventional, war. Al-Qaeda was formally created in the latter years of the Afghan-Soviet war (1979–1989) as the brainchild of Abdullah Azzam, an extreme Islamic theologian of Palestinian origin who provided the intellectual framework for the creation of a transnational militant Islamist organization to carry out global jihad.1
Among the most influential elements of Azzam’s effort was the creation of a transnational Islamist cadre. The idea was brought to him and Osama Bin Laden, a Saudi-born financier who backed the Afghan mujahideen with money and equipment, by successful jihadists who had emerged out of the Afghan civil war.2 The result was the founding, in October 1984, of the Services Bureau (Maktab al-Khidamat), a recruitment and fundraising network designed to supply funds and personnel to the Afghan jihad.3 This network would provide the human and financial pool on which al-Qaeda subsequently relied. Thereafter, in October 1986, Bin Laden began construction of a military training camp near Jaji, a facility that would come to be known simply as “the military base” (al-Qaeda al-Askariyya).4 Al-Qaeda the organization emerged out of these beginnings.5
Azzam was assassinated in Peshawar on November 24, 1989.6 While no perpetrator was ever identified, at least some evidence suggests Jordanian intelligence services were responsible. Analysts have speculated that the KGB, Israeli Mossad, Afghan intelligence or Ayman all-Zawahiri, then head of Egypt’s Islamic Jihad, could also have been responsible for the killing.7 Azzam’s death exacerbated the fault lines of an already fractured Arab-Afghan community. Having preached against authority when deciding on jihad—governments, clerical institutions, even parents—Azzam had become a source of authority with no way to pass on the role. When he died, a vacuum of authority emerged, and al-Qaeda filled the void.8
Beginning in 1989, al-Qaeda began evolving into a truly global organization. When the Soviet Union began to implode, Bin Laden attributed it to his battlefield victories against the Russians – a position that would later become a motivator for the September 11th attacks.9
Saddam Hussein’s annexation of Kuwait in August 1990 led to a schism between Bin Laden and the Saudi government. The U.S. intervened to defend the House of Saud, and in return was allowed to use Saudi territory to evict Saddam from Kuwait, and then to stay on to monitor the subsequent ceasefire.10 Bin Laden easily exploited the question of the permissibility of non-Muslims in the Kingdom, and found a sympathetic ear among significant segments of the Saudi ulema (clergy).11 As a result of the ensuing political tensions with Saudi authorities, Bin Laden was expelled from the Kingdom in 1992, and subsequently migrated to Sudan, which had begun to allow any Muslim into the country without a visa in a display of Islamic solidarity.12 His Saudi citizenship was formally revoked in 1994.13
From its new perch in Sudan, AQ and its supporters conducted three bombings targeting U.S. troops in Aden, Yemen, in December 1992, and claimed responsibility for shooting down U.S. helicopters and killing U.S. soldiers in Somalia in 1993.14 In February of that year, the World Trade Center was attacked for the first time when operatives detonated a bomb underneath the center’s North Tower, intending to knock it into the South Tower. They failed to achieve their primary objective, but six people were killed and over 1,000 were injured. Ramzi Yousef, the man who carried out the failed 1993 World Trade Center attack (and who was the nephew of 9/11 architect Khalid Shaykh Muhammad, or KSM as he is commonly known), was arrested in Pakistan in February 1995.15 When arrested, Yusuf and KSM were in the process of plotting Operation BOJINKA, a coordinated campaign to bring down eleven planes over the Pacific Ocean.16 They also planned to assassinate the Pope and crash planes into U.S. federal government buildings.17
Al-Qaeda’s campaign of violence continued. In November 1995, four Americans training the Saudi National Guard were killed,18 and three dozen others were wounded, in a twin car bombing in Riyadh by Arab-Afghans inspired by Bin Laden.19 Under intense U.S. pressure, the Sudanese regime expelled Bin Laden in May 1996, and he moved back to Afghanistan.20
The second major attack in Saudi Arabia occurred in June 1996. A housing complex in Khobar was bombed, killing nineteen Americans and wounded 500 people. Bin Laden endorsed the attack and issued his “Declaration of War against the Americans Occupying the Land of the Two Holy Place” in August 1996, but he had never actually claimed the attack.
In February 1998, Bin Laden declared that it was the “individual duty” for Muslims to “kill the Americans and their allies… in any country.”21 The subsequent August 1998 bombings of the American embassies in Kenya and Tanzania, which killed hundreds and provoked U.S. cruise missile strikes in Afghanistan and Sudan, communicated that his organization was prepared to act upon this guidance.
On January 3, 2000, al-Qaeda tried to blow up the USS Sullivan with an explosive-laden skiff while the ship was in the port of Aden. The attack failed, but AQ salvaged the explosives and succeeded in its second attempt, this time against the USS Cole, on October, 12, 2000. Seventeen American sailors were killed and nearly 40 others were wounded in that attack.22
The culmination of this decade of sporadic attacks came on the morning of September 11, 2001, when coordinated airplane attacks on New York and Washington organized by al-Qaeda killed nearly 3,000 people from ninety countries and wounded more than 6,000 others.23 In the aftermath of the 9/11 attacks, al-Qaeda lost its safe haven in Afghanistan as the United States, with the support of coalition partners, initiated a broad military campaign that – over the course of several weeks – ousted Afghanistan’s ruling Taliban regime and decimated the Bin Laden network militarily.24 These setbacks, in turn, led to the rise of AQ “franchises” through which the organization could continue its militancy in decentralized fashion. According to the Counter Extremism Project, “the group has established five major regional affiliates pledging their official allegiance to al-Qaeda: in the Arabian Peninsula, North Africa, East Africa, Syria, and the Indian subcontinent.”25
Despite these developments, AQ remained committed to its anti-Western campaign of violence – albeit in more scattered fashion. The first few post-9/11 follow-on plots—the British “shoe bomber” Richard Reid, and the Brooklyn-born would be “dirty bomber” José Padilla (Abdullah al-Muhajir)—were amateurish failures. Meanwhile, U.S. and allied counterterrorism operations continued to erode the organization’s network and capabilities. For instance, KSM, the organization’s de facto chief of external operations, was arrested in 2003 in a joint CIA and ISI effort. (He is currently detained at Guantanamo Bay; the date of his death penalty trial for involvement in the September 11 attacks was originally set for January 2021, but has been postponed as a result of the COVID19 pandemic, with no future date yet set. Other prominent members of AQ leadership detained or killed between 2003 and 2010 include Mustafa Hamid, who was arrested in 2003, Khalid al-Habib and Abu Musab al-Zarqawi, who were killed in 2006, and Saeed al-Masri, who was killed in 2010.26) Most notable, of course, was the death of Osama Bin Laden himself. The al-Qaeda founder and leader was killed at the hands of U.S. special forces operators on May 2, 2011 in an early morning raid in Abbottabad, Pakistan. Leadership of the organization subsequently passed to the group’s second-in-command, Ayman al-Zawahiri.
Nevertheless, the years since 9/11 have borne witness to AQ’s continued lethality and capacity for violence. Per the Counter Extremism Project, Al-Qaeda and its affiliate organizations to date have killed over 2200 people and injured thousands more all over the world.27 Particularly notable attacks linked to the organization include the March 2004 train bombings in Spain, in which 191 people were killed and more than 1800 injured, the March 2005 transit bombings that killed 56 people in England, the August 2007 fuel truck attacks in Iraq that killed more than 300, the Westgate Mall shootings of 2013 in Kenya that killed more than 60 people and injured 80 others, a series of attacks that targeted schools in Nigeria from January to February 2014, killing roughly 200 students, and a suicide bombing in Somalia that killed more than 500 people in October 2017.
Al-Qaeda’s foundational Wahhabi ideology, which endures to this day, evolved out of bin Laden’s religious schooling at university28 as well as the philosophies of the Ikhwan, a militant force of nomadic Saudi tribesmen that is credited with the politicization of Islam during the early 20th century’s colonial period.29 The Ikhwani school of thought focuses on a notional “a pure Islam of the aslaf, and on the idea that individuals and societies that adhere to “true” Islam will prosper in this world,”30 Today, al-Qaeda is a jihadist network that aims to purge the Muslim world of Western influence, destroy Israel, build an Islamic caliphate stretching from Spain to Indonesia, and impose a strict interpretation of Sunni sharia law.31 The group seeks to overthrow corrupt “apostate” regimes in the Middle East, and replace them with what it deems to be “true” Islamic governments.32 This has been a source of conflict and contention within the organization, as there has been debate over what qualifies as corrupt “apostate” regimes. AQ’s primary enemy is the United States, and it ultimately strives to end U.S. support for what it views as corrupted local regimes and push America to withdraw from the region, something that would leave these client states – and perhaps even the U.S. itself – vulnerable.33
It would be fair to say that recent years have proved challenging ones for the Bin Laden network. Militarily, concerted coalition actions have helped to erode the group’s ranks and jeopardize its various post-9/11 bases of operation. Ideologically, meanwhile, recent years have seen the emergence of fierce competition for the group in the “war of ideas,” as its Iraqi offshoot transformed into the Islamic State and subsequently sought to challenge the group for leadership of the global jihadi movement.34 At the same time, however, changes like the “Arab Spring” revolutions that swept over the Middle East and North Africa between 2010-2012, and the ensuing civil wars in Libya, Syria and Yemen all afforded the organization with new opportunities for relevance and permissive environments for operations.
As of March 2020, al-Qaeda and its subsidiary groups were estimated to have between 30,000 and 40,000 fighters situated throughout the world. That figure included as many as 20,000 in Syria, 2,000 in Africa’s Sahel region (roughly 1,000 of whom belong to AQIM), 6,000 in Yemen, 7,000 in Somalia, and 600 in Afghanistan.35 Today, the post-Afghanistan evolution of al-Qaeda can be said to be complete, and the organization – once a unitary movement – now operates predominantly via its various affiliated organizations, franchises and ideological fellow-travelers. These include:
Al-Shabaab (“the Youth”)
Al-Shabaab started gaining ground in Somalia in early 2007, re-infiltrating Mogadishu and seizing neighborhoods of the capital by 2008,36 then consolidating into control over larger tracts of territory in 2009.37 In 2012, the group pledged allegiance to al-Qaeda.38 In its 2020 Country Reports on Terrorism, the U.S. State Department estimated al-Shabaab to have between 7,000 and 9,000 members.39
Funded by “taxes” extracted from the population and revenue from captured resources, al-Shabaab created a repressive Islamist polity.40 In August 2011, while fighting a still ongoing civil war against the Somali government, al-Shabaab withdraw from Mogadishu entirely.41 It then lost Baraawe, its final urban stronghold and the access point to the Indian Ocean, in October 2014.42 Still, al-Shabaab holds territory and engages in violence, primarily targeting the Somali government, throughout the country.43
When the Islamic State arrived in Somalia in 2015, al-Shabaab’s intelligence and counter-intelligence service, the Amniyat,44 was mobilized. The Amniyat arrested IS sympathizers and agents throughout 2016 and 2017. Nevertheless, IS anointed a wilayat (province) in December 2017, and by December 2018 all-out war had been declared by al-Shabaab.45
In July 2019, Qatar was exposed as having sponsored an al-Shabaab attack against its Gulf rival, the UAE, in the port city of Bosaso three months earlier.46 The former head of Somalia’s main intelligence body, the National Intelligence and Security Agency (NISA), said Qatar is the “main sponsor [of al-Shabaab] and uses tricks such as… random deals” to channel money to them.47 NISA itself stands accused of being entangled with elements of al-Shabaab and being behind some of the jihadist group’s attacks in Kenya.48 On December 28, 2019, a bomb went off at a checkpoint entering Mogadishu, killing 85. Al-Shabaab would later claim responsibility for the attack.49 In January 2020, al-Shabaab claimed its first ever attack on a U.S. base in Somalia,50 and in Kenya a British base was attacked.51 The group has also continued its efforts to subvert the Somali state through sporadic attacks on civilian as well as military targets, such as its attempts to storm two military bases in southern Somalia in April 2021.52
Al Qaeda in the Arabian Peninsula (AQAP)
AQAP was al-Qaeda’s most active division in terms of foreign terrorist attacks in 2009 and 2010, but soon after shifted to a local focus. Within Yemen, the group seemed relatively weak, estimated at between 200 and 300 members, albeit with unofficial estimates approximately double that.53 It was, therefore, somewhat surprising when AQAP conquered Ja’ar and Zinjibar in the Abyan governorate in the spring of 2011 and Shaqwa in the late summer of that year.54 Security forces offered no resistance as AQAP advanced; many Yemenis believe the country’s ruler, Ali Abdullah Saleh, allowed AQAP to run riot in order to try to rally support, domestic and foreign, for his regime as it faced down a popular uprising.55
Saleh was finally pushed out in February 2012, and within a few months AQAP was forced into a “strategic retreat” from Abyan province.56 However, this defeat would prove short-lived. Under interim president Abd Rabbuh Mansur Hadi, a Saudi-facilitated national dialogue was initiated to bring the various sectors of Yemen together around a decentralized governing structure, leading to national elections. That process was interrupted in September 2014 by a coup from Ansar Allah, better known as the Houthis, a Shi’a militant movement supported by Iran.57
AQAP capitalized on power vacuums created by Houthi aggression and carved out another mini-emirate, conquering the city of Al-Mukalla in April 2015. At best, the Saudi-led coalition was indifferent to AQAP’s advances, with its focus drawn to the Houthi. Meanwhile, there are local reports that the Coalition prevented tribal fighters who wanted to resist the AQAP takeover of their city,58 and the UAE has publicly admitted that AQAP operatives have been brought within the forces it supports.59
AQAP “further softened its approach by socializing with residents and refraining from draconian rules,” as The International Crisis Group notes. It ruled through a local council and police drawn from city residents, did not display its black banner, and launched infrastructure projects alongside its provision of food and medical care. This governance method—with the emphasis on “Sunni” security against the “Shi’a” Houthi threat, stability, and economic activity—was reasonably popular.60
The coalition, nettled by accusations it was aligning with terrorists to conduct its mission, gradually began to go after Sunni jihadists in Yemen. In April 2016, the coalition ostensibly pushed AQAP out of Al-Mukalla.61 The fact that AQAP avoided fighting for the city meant it retained much of the popularity it had built up,62 and there are accusations that the end of AQAP’s overt control in Al-Mukalla was the result of a negotiated financial settlement.63
Any momentum for anti-AQAP operations was sapped entirely by the UAE’s announced withdrawal from Yemen in July 2019. However, the onset of all-out war between AQAP and IS in Yemen in July 2018 has gravely weakened both groups. As a result, it is unclear how much advantage they can take of any political and security vacuums.64
The franchise’s focus has not been solely internal, however. In 2012, AQAP attempted to recruit a Saudi national to carry out a suicide bombing attack on a plane bound for the United States. However, this attack was thwarted from the very beginning, as a result of the fact that the operative chosen was in fact an agent of the Saudi intelligence services.65
Subsequently, on January 7, 2015, Chérif and Saïd Kouachi, two brothers of Algerian descent, carried out the attack on the headquarters of the French satirical magazine Charlie Hebdo, which had published cartoons mocking Islam. The Kouachi brothers killed twelve of the magazine’s staff, were themselves killed two days, and AQAP claimed direct responsibility for the attacks.66 However, there are doubts that AQAP was in fact involved at all.67
AQAP announced a new leader, Khalid Batarfi, in February of 2020, following the death of the group’s previous chief, Qasim al-Rimi, in a U.S. airstrike. Since the Spring of 2020, fighting has intensified in at least four provinces in Yemen, including in areas where both AQ and IS are present.68
Al Qaeda in the Islamic Maghreb (AQIM)
AQIM publicly announced itself in 2007 under the leadership of Abd al-Malek Droukdel (Abu Musab Abd al-Wadud), a colleague of IS founder Al-Zarqawi. AQIM evolved out of the Group for Preaching and Combat (GSPC), an anti-Algerian government terror faction that fought in that country’s civil war of the 1990s and early 2000s.69
Amid domestic instability in Mali in 2012, AQIM—having gained a foothold in nearby Libya and operating inside Mali through front-groups—occupied an area about the size of Texas in the country’s north and administered it for a number of months.70 By the time France intervened in January 2013, AQIM’s territorial grip had been weakened because the jihadists had tried to implement their program too quickly.71 Droukdel’s main rival was the infamous one-eyed jihadist, Mokhtar Belmokhtar, whose wayward schemes often led to disaster—like the attack siege of the gas plant near Amenas in southeastern Algeria, which (combined with the response by Algeria’s state intelligence service, Le Département du Renseignement et de la Sécurité (DRS)), ended up killing nearly 100 people in the days after the French intervention in Mali.
AQIM was the first al-Qaeda affiliate to reject IS and its caliphate in 2014,72 but the problem in maintaining unity is structural: a vast geography that makes communication difficult, porous borders, revenue streams from drugs and other contraband that incentivize internal competition, and all in the shadow of the DRS. AQIM, while holding to al-Qaeda organizationally, lost important splinters to IS and also ceded control over groups it had nurtured, like Boko Haram in Nigeria.73 In turn, in March 2017, Jama’at Nasr al-Islam wal Muslimin (Group to Support Islam and Muslims, or JNIM), a North African jihadist group formed from the merger of several local Salafi-jihadi groups, pledged allegiance to AQIM.74 Since the beginning of 2020, the intra-jihadi competition in West Africa and the Sahel has intensified.75
On June 3, 2020, Droukdel was killed in Mali during a raid by French forces.76 Subsequently, in November of 2020, the group chose Algerian Abu Obaida Yusuf al-Annabi, the head of its “Council of Dignitaries,” as Droukdel’s successor. 77 As of May 2021, al-Annabi remains the organization’s head.
Hayat Tahrir al-Sham (HTS) and the al-Nusra Front
HTS was formed in January 2017 as a coalition effort between five Syrian jihadist groups, including the former-al-Qaeda affiliate, al-Nusra Front. Upon renouncing its formal affiliation with al-Qaeda in July 2016, Al-Nusra Front renamed itself Jabhat Fath al-Sham (JFS) while continuing to operate under its founder and current leader, Ahmad al-Shara.78 One of the largest HTS contingencies, JFS fighters make up a significant number of HTS members; though figures are inexact, it is estimated their numbers are in the thousands.79
In February 2018 a new jihadist organization, Tanzim Hurras al-Deen (HaD), publicly announced itself and its affiliation with al-Qaeda. As a branch of al-Qaeda, HaD’s ideology matches that of its parent organization. The formation of the new group followed some public, if contained, disputes between HTS and open al-Qaeda loyalists in Idlib at the end of 2017 and a speech from Al-Zawahiri directly critical of Al-Shara.80 However, while evidence exists of the two groups collaborating in their fight against the Syrian government,81 an analytical consensus has emerged that HTS and Hurras al-Deen are functionally competitors and enemies. This is further evidenced by HTS’s apparent June 2020 crackdown on HaD.82
Whether or not Hurras al-Deen represents a true existential threat to HTS’ dominion in Syria has yet to be seen; HaD is functionally 1/10th the size of HTS, with roughly half of its fighters coming from other countries. What’s more, since the group’s founding, U.S. airstrikes have killed several senior leaders of HaD.83 As of June 2020, the U.S. Department of State was estimating that the al-Nusra Front possesses between 1,000 and 5,000 fighters.84
Al-Qaeda on the Indian Subcontinent (AQIS)
Established in 2014 by Asim Umar, a veteran of various south Asian jihadist movements, AQIS was designated as a Foreign Terrorist Organization by the U.S. State Department in 2016 and is today comprised of several hundred members. However, the group has not carried out or claimed an attack since 2014, much of its membership has been killed in drone strikes in tribal Pakistan, and Umar himself was killed in September 2019 in a joint U.S.-Afghan military raid.85
As a January 2019 report from the Soufan Center notes, AQIS maintains relationships with other violent Islamic extremist organizations in South Asia. These include Lashkar e-Taiba (LeT), the Taliban, Harkat ul Jihad e Islami, and Lashkar e Jhangvi.86 Historic funding streams for the group have been charity donations, kidnappings, and individual donations, as well as resources provided by al-Qaeda’s central authority.87
In July 2019, Zawahiri called for extremists in Kashmir to attack Indian forces. On September 11, 2019, al-Zawahiri appealed to Muslims to attack U.S., European, Israeli, and Russian military targets in a video recording.88
On December 6, 2019, a 21-year-old Saudi Air Force officer, Second Lieutenant Mohammed Saeed al-Shamrani, was killed as he attacked fellow students at a training facility in at Naval Air Station Pensacola, Florida. Al-Shamrani murdered three people and wounded eight.89 In an audio statement released on February 2, 2020, AQAP’s leader, Qassem al-Raymi (who had been killed three days earlier in an American drone strike), claimed responsibility. Simultaneously, AQAP released Al-Shamrani’s last will, written in September 2019, and copies of the correspondence Al-Shamrani had with AQAP over an encrypted application.90 The FBI later accessed Al-Shamrani’s mobile telephones, confirmed that these messages were real, that Al-Shamrani had been in contact with Al-Qaeda, and planned the attack for years.91
The timing of al-Qaeda’s first attack targeting the United States in more than a decade makes some sense. With the final destruction of the Islamic State’s physical caliphate in Baghuz in March 2019, al-Qaeda has begun to redouble its efforts to wrestle back its jihadist leadership position. Indeed, while the world was distracted with IS, al-Qaeda was quietly engaged in the groundwork to draw local Muslim communities closer to its worldview.92
FBI Director Christopher Wray offered this read on where al-Qaeda is two months before Pensacola. Whatever “desire” al-Qaeda “maintains… for large-scale, spectacular attacks,” said Wray, “the near term” is “more likely to [see Al-Qaeda] focus on building its international affiliates and supporting small-scale, readily achievable attacks in key regions such as east and west Africa”. Regional prioritization makes sense—the point of the foreign attacks was driving the West out of the region so the non-jihadist governments could be toppled, after all. If possible, al-Qaeda “seeks to inspire individuals to conduct their own attacks in the U.S. and the West,” said Wray, placing them nearer to the low-tech end of the spectrum, quite possibly because the “degraded” state of its leadership.93
Of late, Afghanistan has reemerged as a potential area for the group’s resurgence. A July 2020 UN report warned that al-Qaeda “is covertly active in 12 Afghan provinces,” and estimated that the group “likely commands 400 to 600 fighters” in the country. The group’s South Asian affiliate, AQIS, is believed to have up to another 200 fighters there, with many providing support to the Taliban.94 This presence may expand in the near future as a result of the U.S. decision (made by President Trump and reaffirmed by President Biden) to withdraw forces in 2021 – a development that would position al-Qaeda’s ally, the Taliban, as the potential kingmaker in Afghan politics.96 Meanwhile, a similar retraction of U.S. forces could also take place in Africa, as the Pentagon continues to weigh ending support for ongoing operations there. If such a withdrawal occurs, it will result in less pressure on AQ’s North and Sub-Saharan affiliates from local counterterror coalitions.95 Worryingly, and perhaps because of concerns about America’s departure (and that of France), a number of West African countries signaled in February of 2021 that they were considering opening negotiations with Islamist militants, including those affiliated with al-Qaeda.97
 See generally Thomas Hegghammer, The Caravan: Abdallah Azzam and the Rise of Global Jihad (Cambridge University Press, 2020).
 Mustafa Hamid and Leah Farrell, The Arabs at War in Afghanistan (Hurst, 2015), 65-70; Daniel L. Byman, Testimony before the House Committee on Homeland Security Subcommittee on Counterterrorism and Intelligence, April 29, 2015, https://www.brookings.edu/testimonies/comparing-al-qaeda-and-isis-different-goals-different-targets/.
 John Roth, Douglas Greenburg and Serena Wille, “Staff Report to the Commission: Monograph on Terrorist Financing,” National Commission on Terrorist Attacks Upon the United States, 2004, https://www.9-11commission.gov/staff_statements/911_TerrFin_Monograph.pdf.
 Assaf Moghadam, Nexus of Global Jihad: Understanding Cooperation Among Terrorist Actors (Columbia University Press, 2019).
 Hegghammer, The Caravan, 350-52.
 Thomas Hegghammer, “The Mysterious Assassination That Unleashed Jihadism,” History News Network, November 24, 2019, https://historynewsnetwork.org/article/173697
 “Abdullah Azzam,” Investigative Project on Terrorism, n.d., https://www.investigativeproject.org/profile/103/abdullah-azzam; Bruce Riedel, “Abdullah Azzam, Spiritual Father of 9/11 Attacks: Ideas Live On,” The Daily Beast, September 11, 2011, https://www.thedailybeast.com/abdullah-azzam-spiritual-father-of-911-attacks-ideas-live-on; “Abdullah Azzam,” Counter Extremism Project. Counter Extremism Project, April 26, 2019, https://www.counterextremism.com/extremists/abdullah-azzam.
 Hegghammer, ‘The Mysterious Assassination That Unleashed Jihadism.”
 Bernard Lewis, From Babel to Dragomans: Interpreting the Middle East (Oxford University Press, 2004), 376.
 Lawrence Wright, The Looming Tower: Al-Qaeda and the Road to 9/11 (Vintage, 2007), 156-9.
 For the fullest explanation of Al-Sahwa al-Islamiyya, see: Stephane Lacroix, Awakening Islam: The Politics of Religious Dissent in Contemporary Saudi Arabia (Harvard University Press, 2011).
 Tim Weiner and James Risen, “Decision to Strike Factory in Sudan Based on Surmise Inferred From Evidence,” New York Times, September 21, 1998, https://www.nytimes.com/1998/09/21/world/decision-to-strike-factory-in-sudan-based-on-surmise-inferred-from-evidence.html?searchResultPosition=8.
 Patrick Tyler and Philip Shenon, “Call by Bin Laden Before Attacks Is Reported,” New York Times, October 2, 2001, https://www.nytimes.com/2001/10/02/us/nation-challenged-investigation-call-bin-laden-before-attacks-reported.html.
 U.S. Department of State, “Al Qaeda,” Country Reports on Terrorism 2019, June 2020, https://www.state.gov/reports/country-reports-on-terrorism-2018/#AQ
 Tina Kelley, “Suspect in 1993 Bombing Says Trade Center Wasn’t First Target,” New York Times, June 1, 2002, https://www.nytimes.com/2002/06/01/us/suspect-in-1993-bombing-says-trade-center-wasn-t-first-target.html
 Matthew Brzezinski, “Bust and Boom,” Washington Post, December 30, 2001, https://www.washingtonpost.com/archive/lifestyle/magazine/2001/12/30/bust-and-boom/1109903e-3762-4b78-90a6-d191efd39920/
 “Bojinka Plot,” Encyclopedia Britannica, n.d., https://www.britannica.com/event/Bojinka-Plot; “Suspect in Plot to Kill Pope in Custody, Police Say,” Associated Press, January 1, 1996, https://apnews.com/acebf1db4522e9d234b737894b67ee47.
 Elaine Sciolino, “Bomb Kills 4 Americans in Saudi Arabia,” New York Times, November 14, 1995, https://www.nytimes.com/1995/11/14/world/bomb-kills-4-americans-in-saudi-arabia.html
 Thomas Hegghammer, “Deconstructing the Myth about al-Qa’ida and Khobar,” CTC Sentinel, February 2008, https://ctc.usma.edu/deconstructing-the-myth-about-al-qaida-and-khobar/
 “Osama Bin Laden: A Chronology of His Political Life,” Public Broadcasting Service, n.d., https://www.pbs.org/wgbh/pages/frontline/shows/binladen/etc/cron.html; James Astill, “Osama: the Sudan Years,” Guardian(London), October 16, 2001, https://www.theguardian.com/world/2001/oct/17/afghanistan.terrorism3.
 Paul Todd and Jonathan Bloch, “Back to the Future?” in Paul Todd and Jonathan Bloch, eds. Global Intelligence: The World's Secret Services Today (London: Zed Books, 2003), 90–91, https://books.google.com/books?id=0gZ7sjNakKEC&dq=In+February+1998,+Bin+Laden+declared+that+it+was+the+“individual+duty”+for+Muslims+to+“kill+the+Americans+and+their+allies+…+in+any+country.”&source=gbs_navlinks_s.
 Department of Defense, “U.S. Indicts Two Yemeni Nationals, Al Qaeda Members in USS Cole Attack,” May 15, 2003, https://archive.defense.gov/news/newsarticle.aspx?id=28976
 “September 11 Attack Timeline,” 9/11 Memorial, n.d., https://timeline.911memorial.org/#Timeline/2
 Bruce Riedel, “Al-Qaida today, 18 years after 9/11,” The Brookings Institution, September 10, 2019, https://www.brookings.edu/blog/order-from-chaos/2019/09/10/al-qaida-today-18-years-after-9-11/; Wesley Morgan, “Whatever happen to Al Qaeda in Afghanistan?” Politico, August 15, 2018, https://www.politico.com/story/2018/08/15/al-qaeda-afghanistan-terrorism-777511
 “Al Qaeda.” Counter Extremism Project, n.d., https://www.counterextremism.com/threat/al-qaeda
 Carol Rosenberg, “Trial for Men Accused of Plotting 9/11 Attacks Is Set for 2021,” New York Times, August 30, 2019, https://www.nytimes.com/2019/08/30/us/politics/sept-11-trial-guantanamo-bay.html; “Al-Qaeda’s remaining leaders” BBC News, June 16, 2015, https://www.bbc.com/news/world-south-asia-11489337; John F. Burns and Dexter Filkins, “At Site of Attack on Zarqawi, All That’s Left Are Questions,” New York Times, June 11, 2006, https://www.nytimes.com/2006/06/11/world/middleeast/11scene.html?pagewanted=all; “Group: Al Qaeda says top leader in Afghanistan dies,” CNN, May 31, 2010, https://afghanistan.blogs.cnn.com/2010/05/31/group-al-qaeda-says-top-leader-in-afghanistan-dies/
 “Al Qaeda,” Counter Extremism Project, n.d., https://www.counterextremism.com/threat/al-qaeda
 Rohan Gunaratna, “Al Qaeda's Ideology,” Hudson Institute Current Trends in Islamist Ideology, May 19, 2005, https://www.hudson.org/research/9777-al-qaeda-s-ideology.
 “Al-Ikhwan Al-Muslimeen: The Muslim Brotherhood,” Military Review, July-August 2013, 26–31, https://www.hsdl.org/?view&did=455611.
 Christopher Henzel, “The Origins of Al Qaeda’s Ideology: Implications for US Strategy,” Parameters, Spring 2005, 69–80. https://www.cia.gov/library/abbottabad-compound/AC/AC109E252F2BC6B9C7D32EB31C211AA9_henzel.pdf.
 “Dreaming of a Caliphate,” The Economist, August 6, 2011, https://www.economist.com/briefing/2011/08/06/dreaming-of-a-caliphate.
 Byman, Testimony before the House Committee on Homeland Security Subcommittee on Counterterrorism and Intelligence.
 J.M. Berger, “The Islamic State vs. al Qaeda,” Foreign Policy, September 2, 2014, https://foreignpolicy.com/2014/09/02/the-islamic-state-vs-al-qaeda/.
 Bruce Hoffman and Jacob Ware, “Al-Qaeda: Threat or Anachronism?” War on the Rocks, March 12, 2020, https://warontherocks.com/2020/03/al-qaeda-threat-or-anachronism/; U.S. Department of State, Country Reports on Terrorism 2019, June 2020, https://www.state.gov/reports/country-reports-on-terrorism-2019/#AQ
 Jeffrey Gettleman and Mohamed Ibrahim, “Shabab Concede Control of Capital to Somalia Government,” New York Times, August 6, 2011, https://www.nytimes.com/2011/08/07/world/africa/07somalia.html
 Bohumil Dobos, “Shapeshifter of Somalia: Evolution of the Political Territoriality of Al-Shabaab,” Small Wars and Insurgencies, August 5, 2016, https://www.tandfonline.com/doi/abs/10.1080/09592318.2016.1208282
 “Al-Shabaab Joining Al Qaeda, Monitor Group Says,” CNN, February 10, 2012, https://www.cnn.com/2012/02/09/world/africa/somalia-shabaab-qaeda/index.html.
 U.S. Department of State, “Al Qaeda,” Country Reports on Terrorism 2019, June 2020, https://www.state.gov/reports/country-reports-on-terrorism-2019/#AQ
 Tom Keatinge, The Role of Finance in Defeating Al-Shabaab, Royal United Services Institute (RUSI), December 2014, 4, https://rusi.org/sites/default/files/201412_whr_2-14_keatinge_web_0.pdf
 “Somalia’s al-Shabab rebels leave Mogadishu,” BBC News, August 6, 2011, https://www.bbc.com/news/world-africa-14430283
 Christopher Anzalone, “The Resilience of al-Shabaab,” CTC Sentinel, April 2016, https://ctc.usma.edu/the-resilience-of-al-shabaab/
 Clair Felter, Jonathan Masters, and Mohammed Aly Sergie, “Al-Shabab,” Council on Foreign Relations Backgrounder, January 10, 2020, https://www.cfr.org/backgrounder/al-shabab
 “Somalia’s frightening network of Islamist spies,” BBC News, May 27, 2019, https://www.bbc.com/news/world-africa-48390166
 Caleb Weiss, “Reigniting the Rivalry: The Islamic State in Somalia vs. al-Shabaab,” CTC Sentinel, April 2019, https://ctc.usma.edu/reigniting-rivalry-islamic-state-somalia-vs-al-shabaab/
 Ronen Bergman and David Kirkpatrick, “With Guns, Cash and Terrorism, Gulf States Vie for Power in Somalia,” New York Times, July 22, 2019, https://www.nytimes.com/2019/07/22/world/africa/somalia-qatar-uae.html
 Abuga Makori, “Somalia: Ex-NISA Boss Links Qatar to Financing of Al-Shabaab, Accuses Fahad Yasin of Being ‘Middleman,’” Garowe Online, May 16, 2020, https://www.garoweonline.com/en/news/somalia/somalia-ex-nisa-boss-links-qatar-to-financing-of-al-shabaab-accuses-fahad-yasin-of-being-middleman
 “Somali Intelligence Funding Shabaab to Attack Kenya — Report,” Star, April 17, 2020, https://www.the-star.co.ke/news/2020-04-17-somali-intelligence-funding-shabaab-to-attack-kenya--report/
 Harun Maruf, “Al-Shabab Claims Responsibility for Deadly Bombing in Somali Capital,” Voice of America, December 30, 2019, https://www.voanews.com/africa/al-shabab-claims-responsibility-deadly-bombing-somali-capital
 “Al-Shabaab kills three Americans in attack on US military base in Kenya,” Associated Press, January 5, 2020, https://www.theguardian.com/world/2020/jan/05/al-shabaab-attack-us-military-base-kenya; Stig Jarle Hansen, “Al-Shabaab’s attacks come amid backdrop of West’s waning interest,” The Conversation, January 15, 2020, https://theconversation.com/al-shabaabs-attacks-come-amid-backdrop-of-wests-waning-interest-129706
 Duncan Miriri and Katharine Houreld, “Kenya arrests three men for trying to breach British army camp,” Reuters, January 5, 2020, https://www.reuters.com/article/us-kenya-security/kenya-arrests-three-men-for-trying-to-breach-british-army-camp-idUSKBN1Z404G
 “Somalia: Al-Shabab strikes at two military bases,” Deutsche Welle, April 3, 2021, https://www.dw.com/en/somalia-al-shabab-strikes-at-two-military-bases/a-57092800.
 “Western Counter-Terrorism Help ‘Not Enough for Yemen,’” BBC News, December 29, 2009, http://news.bbc.co.uk/2/hi/8433844.stm
 Grace Wyler, “Al Qaeda Declares Southern Yemeni Province An ‘Islamic Emirate,’” Business Insider, April 1, 2011, https://www.businessinsider.com/al-qaeda-declares-southern-yemeni-province-an-islamic-emirate-2011-3?r=US&IR=T
 “Yemen’s al-Qaeda: Expanding the Base,” The International Crisis Group, February 2, 2017, https://www.crisisgroup.org/middle-east-north-africa/gulf-and-arabian-peninsula/yemen/174-yemen-s-al-qaeda-expanding-base
 Andrew Michaels and Sakhr Ayyash, “AQAP’s Resilience in Yemen,” CTC Sentinel, September 2013, http://www.ctc.usma.edu/posts/aqaps-resilience-in-yemen
 Brian Bennett and Zaid al-Alayaa, “Iran-backed rebels in Yemen loot secret files about US spy operations,” Stars and Stripes, March 25, 2015, https://www.stripes.com/news/middle-east/iran-backed-rebels-in-yemen-loot-secret-files-about-us-spy-operations-1.336632
 “Yemen’s al-Qaeda: Expanding the Base,” The International Crisis Group.
 Bel Trew, “Former al-Qaeda footsoldiers have been allowed into Yemen forces, admits UAE military,” Independent (London), August 16, 2018, https://www.independent.co.uk/news/world/middle-east/yemen-civil-war-al-qaeda-soldiers-uae-military-emirati-a8494481.html
 “Yemen’s al-Qaeda: Expanding the Base,” The International Crisis Group.
 “Yemen conflict: Troops retake Mukalla from al-Qaeda,” BBC News, April 25, 2016, https://www.bbc.co.uk/news/world-middle-east-36128614
 “Yemen’s al-Qaeda: Expanding the Base,” The International Crisis Group.
 Maggie Michael, Trish Wilson, and Lee Keath, “AP Investigation: US allies, al-Qaida battle rebels in Yemen,” Associated Press, August 7, 2018, https://apnews.com/f38788a561d74ca78c77cb43612d50da/AP-investigation:-Yemen-war-binds-US,-allies,-al-Qaida
 Elisabeth Kendall, “The Failing Islamic State Within The Failed State of Yemen.
 Sudarsan Raghavan, Peter Finn, and Greg Miller, “In foiled bomb plot, AQAP took bait dangled by Saudi informant,” Washington Post, May 9, 2012, https://www.washingtonpost.com/world/in-foiled-bomb-plot-aqap-took-bait-dangled-by-saudi-informant/2012/05/09/gIQA9oXIEU_story.html
 “Document: ‘Message regarding the blessed battle of Paris,’” Terrorism.net, January 14, 2015, https://www.terrorisme.net/2015/01/14/document-message-regarding-the-blessed-battle-of-paris/
 An attack by Al-Qaeda in a Western city in January 2015 would be diametrically at odds with AQC’s strategy, and an attack in collaboration with IS is unthinkable (Amedy Coulibaly killed five people in two attacks in Paris around the same time as the Charlie Hebdo shooting. He was a close friend of the Kouachi brothers and had previously pledged allegiance to ISIS). Further, In the video of Coulibaly pledging allegiance to the Islamic State, Coulibaly says he “coordinated” with the brothers for the anuary 8th murder of policewoman Clarissa Jean-Philippe. What’s more, Coulibaly said he supplied the money to the Kouachis for their weapons (“a few thousand euros”) and coordinated his attack with their attack on the offices of Charlie Hebdo, staging them consecutively rather than simultaneously, protracted over three days rather than just a few hours on one day, “so that it’d have more impact”. The Kouachis were, said Coulibaly, “brothers from our team”. See Jane Onyanga-Omara, “Video shows Paris gunman pledging allegiance to Islamic State,” USA Today, January 11, 2015, https://www.usatoday.com/story/news/world/2015/01/11/video-gunman-islamic-state/21589723/; Brian Rohan, Lori Hinnant, and Diaa Hadid, “Video of Paris gunman raises questions of affiliations,” Associated Press, January 12, 2015, https://apnews.com/f953ca926b9f4fee86d241816668bd32.
 Sudarsan Raghavan, “As Yemen's War Intensifies, an Opening for Al-Qaeda to Resurrect Its Fortunes,” Washington Post, February 25, 2020, https://www.washingtonpost.com/world/middle_east/as-yemens-war-intensifies-an-opening-for-al-qaeda-to-resurrect-its-fortunes/2020/02/24/6244bd84-54ef-11ea-80ce-37a8d4266c09_story.html.
 Lianne Kennedy Boudali, “The GSPC: Newest Franchise in al-Qaida’s Global Jihad,” Combatting Terrorism Center North Africa Project, April 2, 2007, https://www.ctc.usma.edu/the-gspc-newest-franchise-in-al-qaidas-global-jihad/
 Zachary Laub and Jonathan Masters, “Al-Qaeda in the Islamic Maghreb,” Council on Foreign Relations, March 27, 2015, http://www.cfr.org/terrorist-organizations-and-networks/al-qaeda-islamic-maghreb-aqim/p12717
 Charles Lister, “Jihadi Rivalry: The Islamic State Challenges al-Qaida,” Brookings Institution, January 2016, 11, https://www.brookings.edu/wp-content/uploads/2016/07/en-jihadi-rivalry.pdf
 Tore Refslund Hamming, “ISIS’s charm offensive toward al-Qaeda in the Islamic Maghreb,” Middle East Institute, December 13, 2018, https://www.mei.edu/publications/isiss-charm-offensive-toward-al-qaeda-islamic-maghreb
 Jacob Zenn, “Demystifying al-Qaida in Nigeria: Cases from Boko Haram’s Founding, Launch of Jihad and Suicide Bombings,” Perspectives on Terrorism, 2017, www.terrorismanalysts.com/pt/index.php/pot/article/view/666/html
 “Al Qaeda branch rallies jihadists to join forces after Mali merger,” Defence Web, March 20, 2017, https://www.defenceweb.co.za/security/national-security/al-qaeda-branch-rallies-jihadists-to-join-forces-after-mali-merger/?catid=49%3ANational%20Security&Itemid=115
 “Jihadist Competition and Cooperation in West Africa,” European Eye on Radicalization, April 3, 2020, https://eeradicalization.com/jihadist-competition-and-cooperation-in-west-africa/
 Benjamin Roger and Farid Alilat. “How AQIM Leader Abdelmalek Droukdel Was Killed in Mali,” The Africa Report, June 8, 2020, https://www.theafricareport.com/29482/how-aqim-leader-abdelmalek-droukdel-was-killed-in-mali/.
 “Al-Qaeda in North Africa appoints new leader to replace Droukdel,” France 24, November 22, 2020, https://www.france24.com/en/africa/20201122-al-qaeda-in-north-africa-appoints-new-leader-to-replace-droukdel.
 “Al-Nusra Front (Hayat Tahrir al-Sham),” Counter Extremism Project, n.d., https://www.counterextremism.com/threat/al-nusra-front-hayat-tahrir-al-sham
 Kyle Orton, “Did Assad Recruit the Leader of Al-Qaeda in Syria?” Counter Extremism Project, August 11, 2016, https://www.counterextremism.com/threat/al-nusra-front-hayat-tahrir-al-sham
 Hassan Hassan, “Two Houses Divided: How Conflict in Syria Shaped the Future of Jihadism,” CTC Sentinel, October 2018, https://ctc.usma.edu/two-houses-divided-conflict-syria-shaped-future-jihadism/
 See Aaron Y. Zelin, “Huras al-Din: The Overlooked al-Qaeda Group in Syria,” Washington Institute for Near East Policy Policywatch 3188, September 24, 2019, https://www.washingtoninstitute.org/policy-analysis/view/huras-al-din-the-overlooked-al-qaeda-group-in-syria; “The Best of Bad Options for Syria’s Idlib,” International Crisis Group, March 14, 2019, 18, https://d2071andvip0wj.cloudfront.net/197-the-best-of-bad-options%20.pdf; “Military Groups Calling Themselves ‘The Finest Factions of the Levant’ Form Joint Operations Room,” Syria Call, October 15, 2018, http://nedaa-sy.com/en/news/9078.
 Simon Hooper and Harun al-Aswad, “British aid worker Tauqir Sharif arrested by HTS in Idlib,” Middle East Eye, June 23, 2020, https://www.middleeasteye.net/news/british-aid-worker-tauqir-sharif-syria-idlib-hts-arrest
 “Hurras al-Din,” Counter Extremism Project, n.d., https://www.counterextremism.com/threat/hurras-al-din
 U.S. Department of State, “Al-Nusrah Front,” Country Reports on Terrorism 2019. June 2020, https://www.state.gov/reports/country-reports-on-terrorism-2019/#ANF
 Ibid.; Sajid Farid Shapoo, Colin P. Clarke, Meriem El Atouabi, et al, “Al-Qaeda in the Indian Subcontinent: The Nucleus of Jihad in South Asia,” The Soufan Center, January 2019, https://thesoufancenter.org/wp-content/uploads/2019/01/Al-Qaeda-in-the-Indian-Subcontinent-AQIS.pdf
 U.S. Department of State, “Al-Qaeda,” Country Reports on Terrorism 2019, June 2020, https://www.state.gov/reports/country-reports-on-terrorism-2019/#AQ
 Katie Benner and Adam Goldman, “F.B.I. Finds Links Between Pensacola Gunman and Al Qaeda.” New York Times, May 18, 2020, https://www.nytimes.com/2020/05/18/us/politics/justice-department-al-qaeda-florida-naval-base-shooting.html.
 Declan Walsh, “Al Qaeda Claims It Directed Florida Naval Base Shooting,” New York Times, February 2, 2020, https://www.nytimes.com/2020/02/02/world/middleeast/al-qaeda-claims-it-directed-florida-naval-base-shooting.html
 U.S. Department of Justice, “Attorney General William P. Barr and FBI Director Christopher Wray Announce Significant Developments in the Investigation of the Naval Air Station Pensacola Shooting,” May 18, 2020, https://www.justice.gov/opa/pr/attorney-general-william-p-barr-and-fbi-director-christopher-wray-announce-significant
 Katherine Zimmerman, Statement before the House Homeland Security Committee Subcommittee on Counterterrorism and Intelligence, July 13, 2017, https://www.criticalthreats.org/analysis/testimony-al-qaedas-strengthening-in-the-shadows
 Christopher Wray, Statement before the House Homeland Security Committee, October 30, 2019, https://www.fbi.gov/news/testimony/global-terrorism-threats-to-the-homeland-103019.
 See Jeff Seldin, “Death of Senior al-Qaida Leader a Major Setback for Terror Group, US Says,” VOA News, October 26, 2020, https://www.voanews.com/south-central-asia/death-al-qaida-senior-leader-major-setback-terror-group-us-says.
 Adam Nossiter, “The Taliban Think They Have Already Won, Peace Deal or Not,” New York Times, March 30, 2021, https://www.nytimes.com/2021/03/30/world/asia/taliban-victory-afghanistan.html.
 Katherine Zimmerman, “Why the US should spend 0.3 percent of its defense budget to prevent an African debacle,” Military Times, March 12, 2020, https://www.militarytimes.com/opinion/commentary/2020/03/12/why-the-us-should-spend-03-percent-of-its-defense-budget-to-prevent-an-african-debacle/
 “West African governments consider talking to regional Islamists,” Financial Times, February 13, 2021, https://www.ft.com/content/8adf00c3-9a55-4027-b760-2fe6bb7aa282.