Twenty-Five Years After 9/11: Is the Age of Global Terrorism Over?

Twenty-five years after 9/11, the global terrorist threat presents a paradox. Terrorism-related deaths are falling, the great jihadist organisations have lost much of their territorial and organisational strength, and the elaborate counter-terrorism machinery created after 2001 has made spectacular transnational attacks far more difficult. Yet it would be dangerous to conclude that the phenomenon has run its course.

The Global Terrorism Index 2026 records 5,582 deaths from terrorism in 2025, a decline of 28% in a year and the lowest figure since 2007. Al-Qaeda no longer possesses anything resembling the infrastructure which enabled it to plan 9/11. The ISIS pseudo-caliphate has disappeared. Its hold over territory in Iraq and Syria was broken years ago.

These are major successes, yet not evidence that transnational terrorism is dead. The more uncomfortable possibility is that terrorism has adapted. It has learnt to disperse, decentralise, migrate geographically and exploit technologies that barely existed when aircraft struck New York and Washington in 2001.

From Organisation to Ecosystem

The terrorist model which produced 9/11 was extraordinarily demanding. It required leadership, financing, training camps, international travel, reconnaissance, communications and prolonged operational preparation. That concentration created vulnerabilities which the global counter-terrorism system subsequently learnt to exploit.

Today's model need not reproduce it.

Al-Qaeda's central leadership has been repeatedly decapitated, but affiliates and associated movements survive across several regions. ISIS lost its territory without losing its brand, ideology or all its networks. UN assessments describe the threat from Al-Qaeda and ISIS as increasingly multipolar, with no single geographical epicentre. They retain the ability to exploit instability and reconnect local grievances with global extremist narratives.

This suggests an important distinction. Terrorist organisations may be destroyed without their supporting ecosystems necessarily being eroded or neutralised.

Such ecosystems consist of ideology, grievance, local conflict, financing networks, organised crime, virtual connectivity and, occasionally, state sponsorship or tolerance. They may remain relatively dormant for years. Their danger lies in their ability to regenerate when political and security conditions become favourable. Thus writing of such organisations will mostly be premature.

The ISIS Warning

Nothing demonstrates this better than ISIS. Mosul fell in June 2014 and within weeks Abu Bakr al-Baghdadi proclaimed a caliphate. At its peak, ISIS controlled substantial territory across Iraq and Syria, attracted foreign fighters and even imposed and collected taxes.

Yet it had not appeared from nowhere. Its foundations lay in Al-Qaeda in Iraq, sectarian alienation, weakened Iraqi institutions, the Syrian civil war and surviving jihadist networks.

ISIS appeared suddenly only to those watching the surface.

Its destruction as a territorial entity was equally dramatic. Military operations, intelligence, air power, local forces and international cooperation dismantled the caliphate. Yet ISIS affiliates remain active, and the UN continues to regard them as a persistent international security threat.

The lesson is important. Terrorism has two lives: the visible organisation and the less visible ecosystem sustaining it. Destroying one does not necessarily eliminate the other.

Geography Has Shifted

The map of terrorism has also changed. Afghanistan, Pakistan, Iraq and Syria dominated international attention through different phases after 9/11. Today, significant jihadist activity has migrated towards parts of Africa, particularly Mali, Burkina Faso and Niger along the southern edge of the Sahara, as well as Somalia and parts of Central Africa.

Weak governance, porous borders, local insurgencies and large spaces where state authority is limited offer opportunities which terrorist organisations instinctively exploit.

South Asia remains another concern. Pakistan was ranked the country most affected by terrorism in the Global Terrorism Index 2026. Afghanistan continues to host multiple extremist networks, while ISIS-K retains both capability and intent despite sustained pressure.

The geography may change; the principle does not. Terrorism gravitates towards spaces where governance is weakest and political violence provides camouflage.

The Training Camp in the Smartphone

The greater transformation may be virtual. The terrorist of the 1990s often needed physical contact with recruiters, trainers and handlers. The potential terrorist of today may require none of these. Propaganda, ideological reinforcement, communication and elements of operational preparation can increasingly occur online.

Remember, the physical training camp has not disappeared; part of it has migrated into the smartphone. Encrypted communications, social media, cryptocurrencies and digital communities have reduced dependence upon elaborate physical infrastructure. Lone actors and small cells consequently pose a different intelligence challenge because they may produce fewer conventional signatures before an attack.

AI adds another dimension. Terrorist experimentation with AI for propaganda and recruitment is already evident, alongside interest in unmanned systems, virtual assets and cyber capabilities. Generative AI can improve translation, propaganda production and research while lowering some technical barriers.

This does not suddenly make terrorists technologically overbearingly competent. It does make the contest more dynamic.

Terrorism Finds New Partnerships

Another development deserves attention. Terrorism increasingly overlaps with other forms of organised illegality. Narcotics networks, arms trafficking, human smuggling, extortion and illegal financial systems can provide infrastructure without requiring a terrorist organisation to create its own. Criminal networks know borders, routes, forged identities and methods of moving money. Terrorist groups need many of the same capabilities.

State sponsorship adds another layer. The experience of South Asia demonstrates how terrorist organisations can survive intense international pressure when protected, tolerated or selectively employed by states seeking strategic advantage without accepting the risks of conventional conflict.

This is particularly relevant in an era of grey-zone confrontation. Terrorism can remain attractive precisely because it provides ambiguity and deniability. Technology may make attribution easier in some circumstances, but the political decision to establish responsibility and impose costs remains far more complicated.

Counter-Terrorism Has Changed Too

The other side of the equation is equally important. The world is vastly better prepared than it was on 11 September 2001.

Intelligence sharing has improved enormously. Passenger movements and financial transactions leave trails. Biometrics make identity manipulation harder. Terror financing is more closely monitored. Communications intelligence, satellite surveillance, drones and precision strike capabilities have transformed the ability to locate terrorist infrastructure and leadership.

Twenty-five years of operations have also created deep institutional experience. Intelligence agencies increasingly search for networks before they mature rather than wait for attacks to reveal them. This explains why another centrally directed operation on the scale of 9/11 is much harder to organise. Yet this very success creates its own danger.

Threat perception inevitably follows experience. When attacks diminish, resources migrate elsewhere. Political attention shifts. Intelligence priorities also change. Institutional memory starts to fade. Today governments are understandably concentrating on conventional war, China, Russia, Ukraine, Iran, West Asia, the Indo-Pacific, cyber threats, artificial intelligence and economic security.

Terrorist organisations do not require equivalent resources. They require patience, sanctuary and opportunity.

The Danger of Declaring Victory

The history since 9/11 therefore offers an uncomfortable conclusion.

Terrorism is not a conventional adversary which can be defeated and made to sign an instrument of surrender. It expands, contracts, fragments, migrates and waits. Organisations disappear while networks survive. Leadership is eliminated while ideology remains. Geography changes and technology provides new means of connectivity.

The sudden emergence of ISIS should remain the warning. Its spectacular rise was preceded by years in which the conditions enabling it were accumulating largely below the threshold of international attention.

Twenty-five years after 9/11, perhaps the greatest achievement of global counter-terrorism is that another attack of comparable scale has not occurred. Its greatest danger would be to interpret that achievement as proof that another one cannot.

Transnational terrorism has not disappeared; it has receded from view. Its networks and ecosystems remain scattered across different geographies, some active, others lying dormant. Conflict, collapsing governance, technological opportunity, sanctuary or state sponsorship can rapidly bring these elements together, allowing a seemingly contained threat to acquire scale with little warning.

Terrorism rarely announces its return. We usually discover that it has returned only when the first explosions rock the state. On 9/11’s 25^th anniversary, there cannot be a better message to the public at large.