Twenty-Five Years On

Twenty-five years after the terrorist attacks of September 11, 2001, we remember. We remember the innocent lives taken, the families changed forever, and the courage of firefighters, police officers, first responders, members of the armed forces and ordinary citizens who acted in moments of unimaginable uncertainty.

On that morning, nineteen al-Qaeda terrorists hijacked four commercial aircraft. Two aircraft struck the World Trade Center towers in New York, one struck the Pentagon, and United Airlines Flight 93 crashed in Pennsylvania after passengers and crew resisted the hijackers. In total, 2,977 victims were killed. They came from more than 90 countries. The attacks were American in location, but international in their human cost and strategic meaning.

September 11 changed the way governments understood security. Aviation security was transformed. Intelligence-sharing expanded. Terrorist financing became a central target. Counterterrorism moved from a specialist concern to a defining element of international strategy. NATO invoked Article 5 of the North Atlantic Treaty for the first and, to date, only time in its history: an attack against one Ally was treated as an attack against all.

“On this anniversary, I stand with the United States of America. I stand with our American friends, colleagues and partners in remembering those who were lost and in reaffirming a principle that remains as relevant today as it was twenty-five years ago: terrorism, violent extremism and ideologically motivated violence must never be normalised, justified or accommodated.”

What Counterterrorism Achieved

The post-9/11 counterterrorism campaign produced major achievements. International intelligence cooperation became deeper and faster. Financial surveillance made it harder for terrorist organisations to move money openly. Military and law-enforcement operations disrupted leadership structures, training areas, facilitators and attack networks. The territorial ambitions of al-Qaeda were constrained, and later the so-called caliphate of ISIS was dismantled through an international coalition and local partners.

Those achievements should not be minimised. They saved lives and reduced the freedom of action of organisations that sought mass-casualty attacks. But they also produced a harder truth: terrorism is not a conventional campaign with a single finishing point. Organisations can be degraded while ideas, networks and grievances survive. Counterterrorism is therefore an enduring responsibility rather than a war that can be declared permanently complete.

Afghanistan: The Difficult Strategic Question

No honest assessment of the twenty-five years since 9/11 can avoid Afghanistan. The Taliban regime that had hosted al-Qaeda was removed from power in late 2001. Yet twenty years later, in August 2021, the Taliban returned to Kabul. Five years after that takeover, United Nations reporting in 2026 continues to describe the Taliban as the de facto authorities exercising effective control over Afghanistan.

How did an international coalition with overwhelming military and technological superiority arrive at that outcome? There was no single error and no single administration that explains it. The failure accumulated across two decades. Objectives changed. Counterterrorism expanded into counterinsurgency; counterinsurgency expanded into state-building; and state-building often relied on institutions, financing and capabilities that could not be sustained independently.

The scale of the investment makes the lesson even more important. According to the U.S. Special Inspector General for Afghanistan Reconstruction, the United States allocated nearly $90 billion in security-sector assistance to the Afghan National Defense and Security Forces from 2002 onward. Yet SIGAR concluded that those forces were never made truly independent and self-sustaining. A force designed in many respects to mirror sophisticated U.S. military structures remained dependent on American airpower, logistics, contractors, maintenance and intelligence.

SIGAR’s broader lessons-learned work was equally stark. Timelines were frequently unrealistic. Western technocratic models were sometimes imposed without sufficient understanding of Afghan political, social and economic realities. Corruption weakened legitimacy. Monitoring and evaluation were inadequate. Success was too often measured by money spent, projects completed or units trained rather than by whether institutions could survive after international support diminished.

The Doha Process and the Collapse of Confidence

The 2020 U.S.-Taliban agreement then changed the strategic psychology of the conflict. The Afghan government was not a central party to the principal U.S.-Taliban negotiation. SIGAR found that the agreement contributed to a sense of abandonment among Afghan forces and the population. The decision to withdraw U.S. military personnel, reduce air support and remove on-site contract maintenance affected not only capability but morale.

This is important because wars are fought through perception as well as firepower. Once Afghan soldiers, officials and communities concluded that the international presence would end, their calculations changed. The Taliban’s calculation changed too.

What Message Did We Transmit?

The question that should concern us is not simply why Kabul fell. It is what adversaries around the world believed they learned from the experience.

My concern is that an unintended message was transmitted: democratic governments operate according to elections, fiscal limits, public fatigue and political pressure, while ideological movements may calculate time differently. An adversary that cannot defeat a democracy militarily may decide instead to outlast its political patience.

That perception is dangerous. It can encourage terrorist organisations, militias and revisionist actors to believe that persistence itself can eventually become a strategy for victory. They study our electoral cycles, our domestic divisions, the durability of our red lines and whether we continue to support partners when the political cost rises.

“The answer cannot be endless military intervention. Withdrawal is not automatically defeat, and negotiation is not weakness. The lesson is more demanding: leaving a conflict requires as much strategy as entering one. A military exit should be tied to a credible political settlement, sustainable local security, clear conditionality, protection of those who cooperated with us and an honest assessment of what follows the departure of international forces.”

Military Superiority Is Not Political Strategy

Afghanistan reminds us that tactical superiority does not automatically produce strategic success. The central question in every intervention must be political from the beginning: what order are we trying to leave behind, who considers it legitimate, who can sustain it, who pays for it, and what happens when outside forces depart?

It also reminds us that local knowledge matters. Institutions cannot simply be imported. Security forces cannot be built around capabilities they cannot maintain. Political legitimacy cannot be purchased. And a strategy cannot remain credible when its objectives change faster than the institutions expected to deliver them.

Reliability Is Part of Deterrence

There is also a moral and strategic responsibility toward the people who stand beside us. Afghan soldiers, interpreters, civil-society representatives, local officials and communities took enormous risks because they believed international commitments had meaning. Future partners elsewhere will study how those commitments ended.

Reliability is therefore part of deterrence. An alliance is measured not only by the solidarity displayed when a crisis begins, but by the credibility maintained when the crisis becomes expensive, difficult and politically inconvenient.

Remembrance Must Produce Preparedness

Twenty-five years after September 11, the international community has learned how to disrupt terrorist networks more effectively. But Afghanistan demonstrates the limits of military power without sustainable political strategy, local legitimacy and strategic endurance.

The correct lesson is neither isolation nor permanent intervention. It is disciplined engagement: clear objectives, realistic timelines, credible alliances, capable local partners, constant evaluation and the political courage to adapt before failure becomes irreversible.

On this anniversary, I stand in solidarity with the United States and with all those who lost loved ones, defended their country and continued the struggle against terrorism. But remembrance must be more than ceremonial. It must make us wiser. It must make our alliances stronger. It must make our strategies more sustainable. And it must ensure that we do not repeat the same mistakes under different circumstances.

“We remember. We learn. We remain vigilant.”

REFERENCES

National September 11 Memorial & Museum. “9/11 FAQs.” Accessed September 10, 2026. https://www.911memorial.org/911-faqs.

National September 11 Memorial & Museum. “September 11, 2001 Commemoration.” Accessed September 10, 2026. https://www.911memorial.org/connect/commemoration.

North Atlantic Treaty Organization. “Collective Defence and Article 5.” Updated November 12, 2025. https://www.nato.int/en/what-we-do/introduction-to-nato/collective-defence-and-article-5.

Special Inspector General for Afghanistan Reconstruction. What We Need to Learn: Lessons from Twenty Years of Afghanistan Reconstruction. SIGAR-21-46-LL. August 2021. https://www.sigar.mil/pdf/lessonslearned/SIGAR-21-46-LL.pdf.

Special Inspector General for Afghanistan Reconstruction. Why the Afghan Security Forces Collapsed. SIGAR-23-16-IP. February 2023. https://www.sigar.mil/pdf/evaluations/SIGAR-23-16-IP.pdf.

United Nations Secretary-General. The Situation in Afghanistan and Its Implications for International Peace and Security. A/80/658–S/2026/99. February 2026. https://digitallibrary.un.org/record/4105103/files/A_80_658–S_2026_99-EN.pdf.

United Nations Assistance Mission in Afghanistan. “Five Years On, Afghanistan’s Future Depends on Inclusive Progress and Sustained International Engagement.” August 13, 2026. https://unama.unmissions.org/en/press-releases/five-years-on-afghanistans-future-depends-on-inclusive-progress-and-sustained.