A Changing Threat: Global Trajectories of Islamist Terrorism since „9/11“ | Infodienst Radikalisierungsprävention | bpb.de

Over the twenty-five years since 9/11, the Sunni jihadist movement has neither remained static nor followed a single linear path. Instead, it has undergone a series of interrelated transformations that have reshaped its structure, leadership, and centers of gravity, as well as its relationship with states that once seemed implacably opposed to it. These changes are uneven and sometimes contradictory: they include both setbacks for key organizations and unexpected gains that would have seemed implausible in the immediate aftermath of 9/11. Together, they have produced a movement that is at once weakened in some respects and more deeply embedded in others, with important implications for how its future trajectory should be understood.

The Sunni jihadist movement has evolved in several notable ways that have shaped its global trajectory since 9/11. First, after more than two decades of pressure and losses, al-Qaida relies on its affiliates to project leadership in the movement and faces a rival, the “Islamic State”. However, the “Islamic State”, also weakened, equally depends on its affiliates to compete with al-Qaida and maintain its relevance. Second, for the first time, the movement writ large is experiencing a sustained dearth of compelling leadership figures to attract new supporters and galvanize existing ones, despite the mobilizing potential of the war in Gaza, in part because al-Qaida and the “Islamic State” lack such figures at the helm of their respective organizations.

The third major change is the geographic shift to sub-Saharan Africa. Throughout the history of the movement, South Asia and the Middle East have often been the locus of activity. But since 2019, al-Qaida and the “Islamic State’s” affiliates in sub-Saharan Africa have engaged in unprecedented levels of violence and caused record numbers of fatalities, all while expanding to destabilize more countries in the region. Consequently, these affiliates are now arguably the most important representatives for both al-Qaida and the “Islamic State”. Unfortunately, there are no indications that the alarming trajectory in sub-Saharan Africa will abate.

Finally, the Sunni jihadist movement has experienced two victories that were unimaginable post-9/11. The Taliban returned to power in Afghanistan in 2021, and then Hay'at Tahrir al-Sham (HTS) took over in Syria in 2024. Though both regimes maintain ties with the foreign jihadists who helped bring them to power, they have also sought international acceptance and succeeded in gaining a modicum of it. In so doing, they have been an inspiration and model for some adherents in the movement, while others reject their approach. There is the potential for further jihadist successes in the coming years, especially in sub-Saharan Africa.

Overall, these four trajectories since 9/11 offer reasons for optimism and concern going forward. Each one of those trajectories will be examined more closely in this article.

Al-Qaida and the “Islamic State’s” Contest

The structure of the Sunni jihadist movement – meaning the organizations that comprise it and their relationships to one another – has changed significantly since 9/11. As was the case in 2001, al-Qaida remains a leader of the movement. But its claim to the position is no longer based, as it once was, on its charismatic leader, substantial resources, or responsibility for the largest terrorist attack in history. Al-Qaida’s founder Usama bin Laden is dead, as is his successor and longtime deputy Ayman al-Zawahiri (Obama 2011; The American Presidency Project 2022). By the time bin Laden died in 2011, al-Qaida was asking other organizations for money, rather than providing it (Bruno 2010). During Zawahiri’s reign, al-Qaida struggled to maintain its position in the movement (Bacon/Arsenault 2019). But since his death in 2022, al-Qaida has not even declared a new leader. Moreover, the group proved unable to strike the United States Homeland again, and it has been over a decade since the last significant al-Qaida-associated attack in Europe.

Instead, al-Qaida’s continued claim to a leadership position in the Sunni jihadist movement depends on its affiliates. The affiliate relationship is itself a product of the post-9/11 environment. Though al-Qaida already had alliances with fellow militant groups, the invention of a relationship in which the leader of another organization pledged bay’ah (a religiously-binding oath of loyalty) to al-Qaida’s emir (leader) occurred in the wake of the 2003 U.S. invasion of Iraq when Abu Musab al-Zarqawi declared fealty to bin Laden and transformed his organization into al-Qaida in the Land of Two Rivers, widely known as al-Qaida in Iraq (Byman 2014; Mendelsohn 2016).. Over twenty years later, al-Qaida has affiliates in East Africa, the Sahel, the Maghreb, the Arabian Peninsula, Syria, and the Indian Subcontinent Importantly, al-Qaida’s affiliates are now self-sufficient and do not depend on al-Qaida for resources, capabilities, or guidance (Byman 2014; The United Nations Analytical Support and Sanctions Monitoring Team 2025). Instead, al-Qaida uses its affiliates’ activities to project continued strength in the face of its substantial losses (Clarke/Broekaert 2025).

However, lacking a declared leader, al-Qaida has no formal mechanism to ensure the continuation of affiliate alliances. When an affiliate’s leader dies, the bay’ah must be renewed by the new leader (Bacon 2023). Such a transition occurred when al-Qaida in the Arabian Peninsula (AQAP) experienced a leadership loss in 2024, with no public renewal of affiliation to al-Qaida core (Al Jazeera 2024). Should al-Qaida core remain without a leader, it risks weakening the bonds with its affiliates (Bacon 2023).

But while al-Qaida remains a leader, it is no longer the leader of the movement. Its status has been contested for over a decade. Its first affiliate – al-Qaida in Iraq (AQI) – evolved into its biggest rival when al-Qaida in Iraq rebranded itself as the “Islamic State” and declared a caliphate and its leader, Abu Bakr al-Baghdadi, as the caliph in 2014 (Hassan/Weiss 2015). The two groups’ ideologies share important characteristics, but they clashed over what causes to prioritize, the timeline for the changes they sought, and leadership differences (Bacon/Arsenault 2019). The alliance between al-Qaida and its first affiliate had long been troubled, but it had finally ruptured the year prior (ibid.). Since then, the “Islamic State” has directly challenged al-Qaida for the mantle of leader of the movement. From 2014 to 2018, its case for that distinction was compelling. Its credentials included territorial control over large swaths of Syria and Iraq, the erection of a quasi-state, and the unprecedented mobilization of tens of thousands of foreign fighters, not to mention its provocative claim of a caliphate (Wilson Center 2019). It also developed its own version of affiliates, calling them “provinces” in keeping with its caliphate declaration, irrespective of whether they controlled any territory (Clayton 2025).

But the “Islamic State” too sustained losses and has since fallen dramatically from its peak. By 2019, it no longer controlled any territory, and its governance apparatus had collapsed. Some of its adherents were killed while others are still languishing in prison facilities in Syria (Wilson Center 2019). Not only has the group lost its so-called caliph, but three of his successors have also since perished (The Soufan Center 2023). The identity of the group’s current leader, Abu Hafs al‑Hashimi al‑Qurashi, is unknown or at least unclear (The United Nations Analytical Support and Sanctions Monitoring Team 2025, p. 5).

With its claim to leadership of the movement similarly eroded, the “Islamic State” also relies on its “provinces” to maintain its stature. While al-Qaida anointed a small number of well-established and vetted groups as affiliates, the “Islamic State” adopted a more liberal and less coherent approach to its provinces. Some of its provinces were also well-established groups, but others were small, poorly organized, and even unable to survive. For example, it declared a “ragtag” splinter from al-Qaida in the Islamic Maghreb to be its province in Algeria in 2014, only for it to be destroyed by Algerian counterterrorism efforts soon thereafter (Warner 2021, pp. 75–81). While al-Qaida usually designated affiliates as its representative for entire regions, the “Islamic State” was inconsistent. For example, it anointed three affiliates in Libya and then designated two separate organizations operating in Mozambique and the Democratic Republic of the Congo as one province, the “Islamic State” in Central Africa Province (Warner 2021, pp. 33–66, 227–276).

Stated plainly, al-Qaida chose quality affiliates, while the “Islamic State” has opted for quantity. Differences in their approaches notwithstanding, both al-Qaida and the “Islamic State” now depend on their affiliates as the basis for their continued claims to leadership within the movement. Indeed, many groups in the Sunni jihadist movement, though not all, are aligned with either the “Islamic State” or al-Qaida.

For al-Qaida, its affiliates in Africa, specifically al-Shabaab in Somalia and Jama'at Nusrat al-Islam wal-Muslimin (JNIM) in the Sahel, are its most consequential partners by virtue of their capability and the threat they pose within Africa. Al-Qaida privately designated al-Shabaab as an affiliate around 2010 and made the relationship public in 2012 (Bin Laden 2010; Roggio 2012). JNIM was born as an al-Qaida affiliate when it was founded in 2017 as an umbrella entity for four main groups operating in the Sahel (National Counterterrorism Center 2022).

Al-Qaida in the Arabian Peninsula has often been a notable affiliate in the network. After its formation in 2009, it played a central role in al-Qaida’s plotting against the West and is responsible for the only successful al-Qaida-associated attack within the United States since 9/11. However, though its intent to attack in the West persists and its rhetoric encouraging such attacks has increased since Hamas’ October 7th attacks on Israel and the subsequent war in Gaza, its capability is limited, and the group is largely confined to Yemen (The United Nations Analytical Support and Sanctions Monitoring Team 2025, pp. 5, 14).

In the face of its losses in the Middle East, the “Islamic State’s” affiliates in sub-Saharan Africa, particularly the “Islamic State” in West Africa Province and the “Islamic State” in Central Africa Province’s wing in the Democratic Republic of Congo, have also become increasingly prominent (Clayton 2025; The United Nations Analytical Support and Sanctions Monitoring Team 2025, pp. 5–6, 8). The “Islamic State” regularly features their high levels of violence or indiscriminate attacks in its propaganda (Serwat et al. 2025). The Islamic State’s affiliate in Somalia is dwarfed by al-Shabaab on the ground but it nonetheless plays a critical facilitation and logistic role in the “Islamic State’s” broader network (Zelin 2024). In terms of projecting a transnational threat, the “Islamic State in Khorasan” fulfills this role, akin to al-Qaida in the Arabian Peninsula for al-Qaida’s network. In addition to disseminating propaganda in multiple languages, it has conducted transnational attacks beyond its geographical core area Afghanistan and Pakistan, striking in Iran, Turkey, and Russia and plotting attacks in Europe and the United States (Palmer et al. 2025, p. 20).

As a result, there are two key differences in the structure of the jihadist movement twenty-five years after 9/11. First, al-Qaida has a genuine rival, one that has even eclipsed al-Qaida, at least from 2014 to 2018. Their competition defines the movement. Second, al-Qaida core no longer leads the movement through its organizational characteristics, such as its leader, its resources, and its capability to inflict violence. Instead, it, like the “Islamic State”, relies on affiliates to project strength and relevance that it no longer possesses as an organization.

The Dearth of Compelling Leaders

While al-Qaida and the “Islamic State” compete with one another for organizational leadership within the movement, there is a notable absence of charismatic figures capable of mobilizing supporters. Since Abu Bakr al-Baghdadi’s death, the Sunni jihadist movement has lacked leaders who can broadly inspire, galvanize, and radicalize adherents. To be clear, there are leaders who effectively run their organizations (Bacon/Grimm 2022). But their authority and following do not extend beyond their groups.

Notably, neither al-Qaida nor the “Islamic State” have such leaders. Al-Qaida’s de facto leader, Sayf al-Adl, has attempted to fill this role, but without formally being appointed as the group’s emir and lacking the requisite charisma or mystique, his efforts have fallen flat. In fact, as stated by the United Nations Analytical Support and Sanctions Monitoring Team, there is even “increasing dissent and dissatisfaction with his leadership” (2025, p. 5). Similarly, the “Islamic State’s” unknown leader cannot fulfill such a role. In the past, the two groups were an important source of leadership figures that garnered a following in the movement, most notably Usama bin Laden and Abu Bakr al-Baghdadi.

Al-Qaida’s affiliates have also produced figures with cachet in the past. The leader of Al-Qaida’s first affiliate, al-Qaida in Iraq’s Abu Musab al-Zarqawi, galvanized adherents and recruits from all over the world through his indiscriminate and brutal violence (Jones 2012, p. 145). Later al-Qaida in the Arabian Peninsula ideologue Anwar al-Awlaki attracted a broad following through his sermons and writings, particularly in English, even though he was not the formal leader of the group (Meleagrou-Hitchens 2020).

There have been leaders that hailed from sources other than al-Qaida or the “Islamic State’s” networks. Egyptian Sayyid Qutb (1906–1966) emerged as an early such leader of the still rudimentary and disorganized movement, mainly through his writings, which continued to resonate long after his execution in Egypt (McGregor 2005; Manne 2016; The Soufan Center 2016). Abdullah Azzam (1941–1989), a Palestinian cleric, served as a movement leader before al-Qaida’s formation through his mobilizing role during the anti-Soviet war in Afghanistan in the 1980s, specifically his calls for all able-bodied men to join the jihad (Hegghammer 2020). In the 1990s, the Afghan Taliban’s Mullah Omar (1959–2013) served as the “Leader of the Faithful” while leading an organization that functioned as a state and welcomed foreign militant groups from all over the world (Dam 2019).

Now there is a vacuum of such figures. The absence of broadly galvanizing leaders has hindered the movement’s ability to exploit the fertile radicalization ground offered by the war in Gaza: a cause that the movement has long championed ideologically but struggled to influence and capitalize on in practice (Bunzel 2023). In fact, the movement currently lacks a mobilizing conflict where supporters can congregate. Such experiences produced multiple movement leaders, including Azzam, bin Laden, al-Zarqawi, and al-Baghdadi. Though the conflict in Gaza has deep resonance within the jihadist movement, adherents were not able to travel there to participate, as they did in Afghanistan, Iraq, and Syria.

Overall, twenty-five years after 9/11, the movement lacks compelling leaders. Though social media offers abundant outlets for groups to spread their ideology and propaganda, no figures since al-Baghdadi have been able to successfully harness it to gain a following that spans the jihadist movement. The result is a more fragmented movement, which has mitigated the potential for mobilization and, by extension, the scope of the threat.

The Epicenter of the Jihadist Movement

The locus of the Sunni jihadist movement – meaning the geographic area with the most concentrated activity – has shifted over time. Until 2018, it was in South Asia, primarily Afghanistan, and the Middle East, particularly Iraq and Syria. But since 2019, the jihadist movement in sub-Saharan Africa has grown and expanded dramatically, while it contracted in South Asia and the Middle East. Consequently, sub-Saharan Africa is now the epicenter of the movement.

Sub-Saharan Africa featured in the movement’s development since the 1990s. In the early 1990s, bin Laden deployed advisers to Somalia to oppose the international intervention and support a Somali Islamist organization in the wake of the state collapse (Watts et al. 2007). Sudan served as a base for the movement from 1992 to 1996 under Hassan al-Turabi’s regime (Tawil 2010, pp. 89–98). Then al-Qaida launched its first attacks in East Africa, the simultaneous suicide bombings of the U.S. embassies in Dar es Salam and Nairobi in 1998 (Commission on Terrorist Attacks upon the United States, 2004, pp. 115–121). But in 2001, the movement was at a low point in the region. The remaining al-Qaida presence was mainly a cell of East African al-Qaida operatives (Department of State 2007). Though the cell was relatively small, its experienced operatives posed an outsized threat, including conducting a suicide attack on a hotel in Mombasa (Kenya) and almost simultaneously firing two shoulder-launched Strela 2 (SA-7) surface-to-air missiles at an airliner departing from Kenya’s Moi International Airport in 2002 (Bryden/Bahra 2019).

The circumstances in the region have since changed dramatically. By 2018, sub-Saharan Africa experienced the same number of jihadist attacks as the Middle East and South Asia. But while violence in those two regions then declined, the number of attacks and deaths in sub-Saharan Africa kept increasing (The Institute for Economics and Peace 2019; BBC 2020). Importantly, the violence is now indigenous, rather than being exported to the region. And it has extended to parts of the sub-continent that were untouched by such violence in 2001. Jihadist activity in sub-Saharan Africa now affects East Africa, the Sahel, the Lake Chad Basin region, Central Africa, and Southern Africa (The Africa Center for Strategic Studies 2025a). It is also encroaching on parts of coastal West Africa (The Soufan Center 2024b).

Virtually all jihadist groups in sub-Saharan Africa are affiliated with al-Qaida or the “Islamic State”. The “Islamic State” has five affiliated organizations in sub-Saharan Africa (Warner 2021). Al-Qaida only has two affiliates, al-Shabaab in Somalia and JNIM in the Sahel, but they are two of the most powerful jihadist organizations in the world. Consequently, jihadist violence in Somalia and the Sahel was responsible for the vast majority of fatalities since 2022 (The Africa Center for Strategic Studies 2025a).

Perhaps most worryingly, there are no signs that violence in the region is abating. In fact, it reached new records in 2025 (The Africa Center for Strategic Studies 2025a). At the same time, more countries are being affected, and the strength of the African jihadist organizations is growing (The Africa Center for Strategic Studies 2025b).

Jihadist Victories

Since 9/11, two jihadist groups have achieved victories, both militarily and diplomatically, in Afghanistan and Syria. The Afghan Taliban regained power in Afghanistan in 2021, while HTS took power in Syria in late 2024. The impact of these successes on the movement is, however, complicated.

The Taliban and HTS’s achievements provided a morale boost, particularly for al-Qaida-aligned groups. In fact, HTS watched the Taliban takeover “carefully”, and HTS leader Ahmed al-Sharaa saw the Taliban’s return to power as a source of inspiration (International Crisis Group 2021; BBC 2024). They both succeeded after long and arduous military conflicts, giving hope to groups in the same predicament and drawing praise (Critical Threats 2021; International Crisis Group 2021; Joscelyn 2021).

Both organizations not only control states, but they have gained some international acceptance, which invokes skepticism among parts of the movement and outright hostility from “Islamic State”-aligned elements (Farooq n.d.). HTS has gained some international acceptance relatively quickly in part because of al-Sharaa’s “charm” offensive and also because it ended its affiliation with al-Qaida years before taking power (Lister 2018; The Soufan Center 2024a). The Taliban, in contrast, was never willing to abdicate al-Qaida. But even its regime has diplomatic ties with over forty countries and has been formally recognized by Russia (Goldbaum 2024; Yawar 2024; Bahiss 2025; Shamim 2025; Thomas 2025).

Another similarity is that both regimes continue to host foreign militants who fought alongside them during their insurgencies, though they have not adopted open door policies welcoming an influx of new militants. The Taliban pledged to prevent attacks emanating from Afghanistan though it has allowed a “permissive environment” for al-Qaida and other foreign militant groups under its rule (U.S. Department of State 2020; The United Nations Analytical Support and Sanctions Monitoring Team 2025, p. 16). In particular, it has provided a safe haven for the Pakistani group Tehrik-e-Taliban Pakistan (TTP), which has enabled the TTP to launch a renewed offensive in Pakistan (Khan/Ahmed 2025). In addition, al-Qaida has erected training facilities in Afghanistan and retained an intent to conduct attacks in the West as it seeks to rebuild its capability (Roggio 2024; Joint CT Assessment Team National Counterterrorism Center 2025; The United Nations Analytical Support and Sanctions Monitoring Team 2025, p. 17). Both HTS and the Taliban have also integrated some foreign militants into their security apparatuses (The United Nations Analytical Support and Sanctions Monitoring Team 2025, pp. 12, 17).

Notably, they both also face a threat from the “Islamic State”. The “Islamic State” was – and remains – an avowed enemy of HTS. HTS splintered from the Islamic State in 2013, an acrimonious break that caused deep-seated enmity that persists today. Operating largely as an insurgent group, the “Islamic State” seeks to destabilize the HTS government and Syria writ large. Though it remains far from its peak, the “Islamic State” remains capable of conducting attacks even in Damascus, such as the June 2025 attack on a church on the outskirts of the city, and against the residual U.S. military presence, most notably the killing of three Americans in December 2025 in Palmyra (Drevon 2025; Hawach 2025). With an estimated 9,000 fighters and supporters languishing in prison facilities in Syria – though some have been transferred to Iraq in recent months and more are slated to be transferred in the coming months – the group has the potential to resurge quickly, if its prison break operations are successful (Clayton 2025).

In Afghanistan, the “Islamic State in Khorasan” undertakes a similar mission against the Taliban. The regime has succeeded in reducing the “Islamic State’s” affiliate operations within Afghanistan. The “Islamic State in Khorasan’s” violence surged the year the Taliban took power in 2021 and remained high the following year. But since 2023, the group’s attacks within Afghanistan have significantly declined, while it has exported violence elsewhere and expanded the quantity of its propaganda and the number of languages used (The Institute for Economics & Peace 2025, pp. 5, 74, 77–80).

The “Islamic State” does not pose a threat to regime survival in either country, but it is capable of inflicting blows that embarrass both governments and raise questions about their ability to protect the civilian population or even their own personnel. Moreover, the “Islamic State” and its affiliates’ ambitions extend well beyond Syria and Afghanistan.

Forecast for the Movement

Given the discussion about the state of the Sunni jihadist movement twenty-five years after 9/11 and how it has changed over time, there are five key areas to watch going forward:

1. Al-Qaida and the “Islamic State’s” competition to lead the movement. Both organizations have been seriously degraded but are actively seeking to rebuild. For its part, al-Qaida has a safe haven in Afghanistan and powerful affiliates in Africa. The “Islamic State” is looking for exploitable opportunities in Syria, particularly HTS missteps or successful prison breaks, while looking to affiliates to engage in violence it can tout.

2. The leadership vacuum. The rise of a charismatic figure who captures the imagination of the movement is difficult to predict. There is no common profile for those who have previously played this role. But such a figure could be transformative in activating the next generation of the movement.

3. The emergence of a mobilizing conflict. Wars in Afghanistan, Iraq, and Syria mobilized new generations of recruits, provided forums for adherents to gain experience and develop ties with one another, enabled the rise of charismatic leaders, and inspired violence in the West. To date, jihadist conflicts in sub-Saharan Africa have not garnered widespread ideological traction beyond the region. Though Gaza had sufficient resonance, there was no viable way to participate, limiting its mobilizing impact.

4. The alarming trajectory in sub-Saharan Africa. The forecast for the region is grim, particularly for civilians. There are no interventions on the horizon to change that reality. The effects of destabilized governments and emboldened affiliate organizations will likely not remain contained within Africa over the long term.

5. Another jihadist victory? Should another jihadist victory occur, it will most likely be in Africa. Analysts have already warned of this possibility in Mali and Somalia (Bryden 2025; Faucon 2025). In such a scenario, the victorious jihadist group may seek to follow HTS’s path or the Taliban’s current approach, or it may be more hostile to the international system in ways that offer the movement new opportunities.