Twenty-five years after the September 11, 2001 terrorist attacks fundamentally transformed the global security environment, terrorism has not disappeared. Instead, according to a major new assessment by Atlantic Council experts, the threat has evolved from large, centrally organised terrorist organisations into more dispersed, localised and technologically enabled networks.
The Atlantic Council’s report, “The State of Terrorism, 25 Years After 9/11,” brings together the assessments of 25 experts examining how terrorism has changed since the attacks that killed nearly 3,000 people and triggered the United States-led “war on terror.”
The report concludes that while major terrorist organisations such as al-Qaeda and ISIS no longer possess the same level of centralised power and operational capacity they held at the height of their influence, their affiliated networks remain resilient. Terrorist groups have adapted to changing political, military and technological conditions, exploiting weak governance, local conflicts, illicit economies, social grievances and digital platforms to sustain recruitment, propaganda and operations.
Afghanistan remains a particular concern. Atlantic Council experts examining South Asia warn that the terrorist landscape in the region is less dangerous in some respects than it was in the years immediately preceding September 11. Al-Qaeda has been significantly weakened, while many of the more than a dozen militant and terrorist organisations operating across Afghanistan and Pakistan have limited operational capabilities.
However, the report cautions against interpreting these developments as evidence that the underlying threat has disappeared. Michael Kugelman, a senior fellow for South Asia at the Atlantic Council, argues that Afghanistan continues to provide a favourable environment for armed and terrorist groups. The Taliban administration, which has governed Afghanistan again for approximately five years, maintains relationships, ties or alliances with a range of militant organisations operating in the region, including Central Asian jihadist organisations and Pakistani militant groups.
The continued presence and activity of such groups, the experts argue, demonstrate the enduring security challenges created by weak governance, limited counterterrorism capacity and the absence of effective mechanisms to prevent terrorist organisations from using Afghan territory for recruitment, planning and other activities.
The report therefore identifies Afghanistan as likely to remain an important environment for terrorist activity in the near future.
Among the most serious concerns identified by the report is Islamic State–Khorasan Province (IS-K). Atlantic Council experts describe IS-K as one of the region’s most capable terrorist organisations. Although sustained Taliban counterterrorism operations have reduced the number of attacks carried out by the group in recent years, IS-K has demonstrated resilience under pressure.
The group continues to possess capabilities for recruitment, propaganda production and operational planning. More significantly, experts warn that its ambitions and networks extend beyond Afghanistan and the wider South Asian region.
IS-K has demonstrated an ability to develop cross-border networks and has sought to exploit political, economic and social vulnerabilities in Central Asian countries. The report notes that recruits from countries including Tajikistan have been connected to IS-K-linked plots and attacks in locations as diverse as Europe, the Philippines and the United States. The experts therefore caution that pressure on IS-K has not eliminated the organisation’s underlying capacity to regenerate and conduct operations.
One of the most important conclusions of the Atlantic Council assessment is that the nature of terrorism has fundamentally changed since 2001. Before the September 11 attacks, terrorism was associated with a wide range of separatist, nationalist, revolutionary and religious organisations. Al-Qaeda introduced a particularly consequential model: a transnational non-state organisation capable of exploiting weakly governed territories while planning complex attacks against targets located far from its operational base. Today, however, terrorist organisations increasingly operate through decentralised structures.
Rather than relying exclusively on a single command hierarchy, groups such as al-Qaeda and ISIS have developed networks of affiliates and associated organisations. Local conflicts, insurgencies, territorial disputes, criminal economies and extremist ideologies can intersect to create conditions in which terrorist organisations survive even when their central leadership is weakened.
The internet and social media have accelerated this transformation. Individuals can now encounter extremist propaganda, communicate with like-minded communities and become radicalised without ever establishing direct contact with the leadership of a major terrorist organisation. This has made the threat more difficult to identify, attribute and prevent.
The result is a security environment in which terrorist activity may emerge from a combination of established organisations, local militant groups, self-radicalised individuals, criminal networks and other actors rather than from a single identifiable command structure.
The Atlantic Council assessment does not portray al-Qaeda or ISIS as the organisations they were at their peak. Both have lost significant territory, leadership structures and operational capabilities. Nevertheless, their ideological influence and affiliated networks remain active. The report points to the continued strength of al-Qaeda-linked networks in parts of Africa, including an affiliate in Mali that controls significant territory. It also identifies Somalia-based networks associated with ISIS as important components of the group’s global activity.
The experts emphasise that the continuing danger lies not simply in the ability of these organisations to conduct large-scale attacks themselves, but in their capacity to inspire violence, recruit supporters, distribute propaganda and establish relationships with local militant organisations. Their ability to exploit modern communication technologies has further increased the speed and geographical reach of extremist messaging.
The report also reassesses the record of the US-led “war on terror” over the past quarter-century. Atlantic Council experts do not offer a single verdict on whether the campaign should be considered a success or failure. Instead, they argue that its record is considerably more complex.
Omer Rafiq, a non-resident senior fellow at the Atlantic Council, argues that the United States achieved numerous tactical successes, including the disruption and elimination of important terrorist leaders and networks. However, successive US administrations failed to establish a clear definition of what victory in the “war on terror” would ultimately mean or under what conditions the wars launched after September 11 would end. Rafiq estimates that more than 900,000 people were killed in direct violence associated with wars following the September 11 attacks, including more than 7,000 US service members.
From this perspective, the central weakness was not necessarily the ability of US forces to conduct military operations, but the absence of a clearly defined strategic end state.
The wars in Afghanistan and Iraq also profoundly affected US foreign policy. The withdrawal of American forces from Afghanistan, combined with the legacy of the Iraq war, has contributed to greater public scepticism in the United States regarding prolonged foreign military interventions.
Technology is emerging as one of the most significant factors likely to shape terrorism over the next decade. Atlantic Council experts warn that terrorist organisations can use artificial intelligence to produce propaganda, translate extremist material, identify and target vulnerable audiences, and improve recruitment campaigns.
Generative AI may also lower the technical barriers facing individuals or organisations seeking specialised knowledge. The report notes that ISIS-linked actors have already experimented with AI-enabled propaganda and distribution. As generative and automated systems become more sophisticated, terrorist organisations could potentially produce large quantities of personalised and targeted extremist content at unprecedented speed.
This creates a new challenge for governments, technology companies and security agencies: extremist organisations may increasingly be able to tailor propaganda to specific languages, communities, interests and psychological vulnerabilities without requiring large human teams.
The proliferation of inexpensive and commercially available drones is another emerging security concern. According to the experts, small unmanned aircraft could provide terrorist organisations with relatively accessible means of targeting crowded locations, infrastructure and symbolic sites.
The report also highlights the possibility of terrorist organisations combining physical and cyber capabilities. Rather than a single catastrophic cyber event resembling the concept of a “cyber 9/11,” future attacks could involve cyber operations designed to facilitate physical violence for example, by stealing information, disrupting communications, interfering with security systems or undermining emergency response capabilities.
Such hybrid operations could make attacks more difficult to detect and respond to, particularly where critical systems depend heavily on interconnected digital infrastructure. Water supplies, electricity networks, transportation systems, healthcare facilities and communications infrastructure are becoming increasingly dependent on digital technologies. The Atlantic Council experts warn that outdated systems and weak cybersecurity could create vulnerabilities that terrorist organisations or other hostile actors may seek to exploit.
Potential threats include malware, ransomware, disruption of navigation systems, interference with communications and the use of AI-enabled tools. The growing convergence between physical and digital infrastructure means that an attack against a computer system could potentially produce consequences in the physical world. For governments, protecting critical infrastructure will therefore require not only traditional physical security but also stronger cybersecurity, continuous monitoring and resilience planning.
The report identifies technological change as an important factor in the evolution of terrorist financing. Experts stress that cryptocurrencies have not replaced traditional sources of terrorist funding. Cash, state support, informal financial systems and other established methods remain significantly more important. Nevertheless, digital currencies and alternative payment technologies can create additional avenues for moving money outside traditional financial-monitoring mechanisms.
The report notes that organisations including IS-K have used privacy-focused cryptocurrencies to solicit donations. The experts therefore argue that counterterrorism financing mechanisms must continue to evolve alongside financial technology, ensuring that emerging payment systems do not create significant blind spots for law-enforcement and intelligence agencies.
The threat facing the United States is considerably different from that of 2001. According to the Atlantic Council experts, the appeal of Salafi-jihadist ideology has declined compared with two decades ago, while al-Qaeda and ISIS have less capacity to organise and execute large-scale attacks inside the United States.
However, the threat has not disappeared. Self-radicalised individuals, lone attackers and domestic extremist movements continue to pose challenges because they may operate without meaningful connections to established terrorist organisations.
Some experts also identify an increasing threat from state-backed militant actors, particularly groups supported by Iran. This changing threat environment requires counterterrorism strategies that extend beyond the traditional focus on foreign terrorist organisations and overseas military operations.
Another concern identified by the report is the potential erosion of counterterrorism capabilities as US strategic attention increasingly focuses on competition with China and Russia. Atlantic Council experts warn that funding, personnel and operational resources previously devoted to counterterrorism have declined in some areas. This includes regions such as South Asia and Africa, where terrorist organisations and affiliated networks remain active. A reduced intelligence and operational presence could make it more difficult for Washington and its partners to identify emerging terrorist networks before they become significant security threats.
The experts therefore caution against allowing counterterrorism to disappear from the strategic agenda simply because the threat no longer resembles the highly visible al-Qaeda threat of 2001.
The Atlantic Council report emphasises that international cooperation was central to counterterrorism efforts over the past 25 years and will remain indispensable in the future. Intelligence sharing, financial monitoring, law-enforcement cooperation, diplomatic coordination and joint security efforts have played a critical role in disrupting terrorist networks.
However, the nature of cooperation must evolve. Governments increasingly need to address self-radicalisation, domestic extremist movements, online propaganda, social-media ecosystems, emerging technologies and new forms of terrorist financing. The experts predict that attacks conducted by inspired individuals, lone actors and domestic extremist networks could become more prominent, making early identification and international information sharing increasingly important.
Twenty-five years after September 11, the global terrorist threat is neither the same nor necessarily smaller in every respect. The era of large, centrally controlled organisations capable of openly holding territory and orchestrating complex attacks from a single command structure has given way to a more fragmented environment.
Terrorist networks are increasingly localised, decentralised and digitally connected. Afghanistan remains a significant concern because of the continued presence of terrorist and militant organisations and the challenges surrounding effective counterterrorism governance. Parts of Africa and the Middle East likewise remain important theatres for terrorist activity.
At the same time, technology is creating new possibilities for extremist organisations. Artificial intelligence, drones, cryptocurrencies, social media and cyber capabilities could significantly alter how terrorist groups recruit, communicate, finance themselves and conduct operations. The central lesson of the Atlantic Council’s assessment is therefore clear: the terrorist threat has not disappeared; it has evolved.
The challenge for governments is no longer limited to dismantling large organisations such as al-Qaeda and ISIS. It increasingly involves understanding and disrupting complex ecosystems in which terrorist organisations, local insurgencies, criminal economies, digital platforms, self-radicalised individuals and geopolitical conflicts can interact.
As the world marks the 25th anniversary of the September 11 attacks, the report serves as a reminder that counterterrorism cannot rely solely on the strategies of the past.
A durable response will require sustained intelligence capabilities, effective international cooperation, resilient critical infrastructure, responsible management of emerging technologies and policies capable of addressing the political, social and economic conditions that allow extremist networks to survive.
