BRIEFS

25 years since 9/11: How terrorist threat has changed

Read time: 10 MIN.

11.09.2026

Twenty-five years after 9/11, the threat that reshaped the international counterterrorism system has changed substantially. That system was designed largely to confront a centralized transnational organization with a coherent ideology, territorial sanctuary and the ambition to strike a distant enemy. Governments responded by designating organizations, disrupting networks, denying sanctuary and challenging extremist narratives. Those tools remain necessary, but the model behind them no longer describes much of the threat.

The headline figures for 2025 illustrate the problem. Data from the Institute for Economics & Peace (IEP) indicate that terrorism deaths fell by 28 per cent, from 7,714 to 5,582, across 2,944 incidents. Eighty-one countries improved and 19 deteriorated. Yet 11 countries recorded reductions greater than the entire net global decline, while fatalities rose elsewhere.

Conflict-affected states accounted for 98 per cent of all deaths, and the decline in war zones and minor-conflict zones explains the whole global reduction. This was a collection of sharply different regional developments, not a uniform retreat in terrorism.

The difference matters for policy. A falling global total can invite broad conclusions about success, even when the movement is concentrated in a few conflict zones and accompanied by deteriorating conditions elsewhere. National and regional patterns reveal whether armed groups are losing strength, redirecting their violence or moving into activities that standard terrorism indicators capture poorly. They determine where resources are still required.

The Sahel: Fewer attacks, greater pressure on the state

The Sahel accounted for more than half of terrorism deaths in 2025, compared with less than 1 per cent in 2007. Burkina Faso recorded the world’s largest national decline: 686 fewer deaths, a fall of 45 per cent. The change in targets, however, is more revealing than the national total. Civilian deaths fell by 84 per cent, from 996 to 157, while deaths among police and military personnel rose from 419 to 643. Average fatalities per incident increased from 10.5 to 18.9. Attacks became less frequent, more lethal and more concentrated on the state.

This pattern can accompany territorial consolidation. Terrorist groups may reduce attacks on civilians as they seek local acceptance, while intensifying attacks on security forces and using economic blockades to pressure cities. Jamaat Nusrat Al Islam Wal Muslimeen (JNIM) caused 1,274 deaths in 147 incidents during 2025. Seventy per cent of those killed were military or police personnel. Its fuel blockade of Bamako and expansion into the gold-producing Kayes region show a campaign directed at territory, state access and economic life as well as casualties.

Hybrid actors and mobile capabilities

The Houthis show why older organizational categories are also under strain. The movement has developed from an Iranian client into a more autonomous regional actor. It assembles one-way attack drones in Yemen with globally sourced components, runs procurement operations through Djibouti and has built a centralized smuggling system. It rules over an area that is home to roughly 20 million people and maintains about 25,000 regular troops. Iran remains important for advanced missiles and drones, while some reporting also suggests a broader Houthi reliance on Tehran for funding and operational support.

The movement has transactional relationships with Al Qaeda in the Arabian Peninsula despite the sectarian divide. It has also become a supplier of expertise: Houthi engineers have trained Somalia’s Al Shabaab in improvised explosive device production and drone modification, while an arms pipeline from Yemen has strengthened Al Shabaab’s capabilities. Al Shabaab itself operates as an insurgency, a terrorist organization and a parallel state. Such actors cannot be understood through designation alone. Their power also comes from territory, logistics, administration and relationships with other armed groups.

Capability now moves between conflicts without requiring a shared organization or ideology. Artificial intelligence may follow a similar path, although the evidence remains uneven. Evidence suggests adoption by lone actors and small cells is incremental, with physical execution still the main constraint. Interviews with former Boko Haram operatives offer a different picture: Dedicated AI units, allocated funding and rank-based access controls within Daesh West Africa Province (ISWAP) and Jama’atu Ahlis Sunna Lidda’awati Wal Jihad (JAS), which was the original faction of Boko Haram. Both findings may be accurate. Access to AI does not automatically create operational capability. Organizational structure, resources and freedom from disruption determine whether groups can use it systematically. Hence, the most consequential adoption may occur where governance is weakest, not where the technology is most widely available.

The West: Unclear motives, concentrated lethality

Western states moved against the global trend in 2025. Terrorism deaths rose by 280 per cent to 57, the first total above 50 since 2019. The United States recorded 28 deaths, its highest figure since 2019, while Australia experienced its deadliest terrorist attack on record.

Attribution also became harder. Forty per cent of Western attacks could not be linked to a group or ideology, and fewer than 20 per cent could be attributed to a specific organization. Worldwide, by contrast, identifiable actors accounted for 78 per cent of incidents and 89 per cent of deaths. In the United Kingdom, mixed, unstable or unclear referrals — cases that don’t fit a coherent single ideology, often driven by personal crisis or fluid, contradictory grievances rather than a defined political or religious cause — are now the largest Prevent category at 34 per cent, ahead of extreme right-wing cases at 21 per cent and Islamist cases at 10 per cent. Prevent is one of the four pillars of the UK’s CONTEST counter-terrorism strategy, designed to identify and support individuals vulnerable to radicalisation before they become involved in terrorism.

Lone actors carried out 93 per cent of fatal attacks in the West over the past five years and were three times more likely than multi-person plots to complete an attack.

Ideological ambiguity does not mean ideology has lost its lethal force. Religiously motivated attacks made up just over 10 per cent of Western incidents over the past two decades but caused 527 of 990 deaths, or 53 per cent.

Assessment

These trends are connected. Territorial control gives armed groups room to restrict movement, shape economic life, sustain supply networks and develop administrative functions. That organizational depth helps them absorb new technology and transfer expertise across borders. Hybrid actors can combine insurgency, terrorism and governance, while Western lone actors increasingly operate without a clear organisational home. In both settings, the boundaries that once guided assessment are becoming less reliable.

Counterterrorism policy still carries assumptions formed around discrete, hierarchical organizations projecting violence from sanctuary. Today’s threat also includes armed movements consolidating territory, quasi-state actors, capabilities travelling between conflicts and isolated attackers whose motives resist easy classification. Assessment must therefore look beyond incident and fatality totals to target selection, territorial reach, economic coercion, administrative control and technical capability.

The fall in deaths during 2025 may represent genuine progress in some theatres. In others, it may mean that armed movements have changed whom they attack and how they exercise power. Twenty-five years after 9/11, the challenge is not simply to identify fewer or more attacks. It is to recognize when the threat has changed form.