The September 11, 2001 was not only one of the most dramatic days in contemporary history. It was also a military watershed.

Today, September 11, 2026, exactly 25 years have passed since the attacks against the United States. Four commercial aircraft were hijacked: two struck the Twin Towers of the World Trade Center in New York, one hit the Pentagon, and a fourth crashed in Pennsylvania after passengers fought back. Almost 3,000 people lost their lives.

From that day on, the very perception of threat changed. It was no longer necessary for an army to cross a border with tanks and divisions to strike a great power. A non-state terrorist organization had demonstrated the ability to use civilian tools as weapons and carry out a strategic attack directly on U.S. territory.

The military world would never be the same again.

NATO Article 5 for the first time in history

The first consequence came immediately.

On September 12, 2001, for the first time since the birth of the Atlantic Alliance, NATO decided that the attacks could be considered an attack against all Allies under the Article 5 of the Washington Treaty, if the external origin of the attack were established.

On October 2, the involvement of the international terrorist network of Al-Qaeda was confirmed and Article 5 became fully applicable.

Even today, September 11 remains the first and only activation of Article 5 in NATO history.

It was a historic turning point: a terrorist organization was considered capable of producing strategic effects comparable to those of a traditional military aggression.

From Afghanistan a new war emerges

In October 2001, the United States launched Enduring Freedom in Afghanistan.

The initial objective was to strike Al-Qaeda, deprive it of the bases from which it had planned the attacks, and overthrow the Taliban regime that guaranteed its protection.

This marked the beginning of what would be called the Global War on Terror, destined to characterize much of the following twenty years.

Italy also participated in the operations. The Italian Armed Forces were present in Afghanistan as part of Enduring Freedom and subsequently the ISAF mission.

In 2003, the Italian Task Force “Nibbio” deployed approximately one thousand military personnel; the 187th Parachute Regiment “Folgore” replaced the 9th Alpine Regiment in June of the same year.

For an entire generation of Western military personnel, Afghanistan and later Iraq would become the primary operational laboratory.

The rise of Special Forces

One of the most evident effects of September 11 was the growing centrality of Special Forces.

The hunt for terrorist organizations required characteristics different from conventional warfare: intelligence, infiltration, surveillance, night operations, direct action, hostage rescue, and the ability to strike extremely small and mobile targets.

Special Forces operators could work together with intelligence, aviation, and local forces to identify a target and enable the intervention of an aircraft or assault team.

The concept of joint operations, already existing, became increasingly tighter and faster.

Operations against the leaders of jihadist organizations also led to the development of a true global machine dedicated to target search: identify, locate, neutralize, and immediately exploit collected information to reach the next target.

The drone revolution

If today drones represent one of the dominant elements of the battlefield, an important part of their modern military evolution passes through the wars following September 11.

Remotely piloted aircraft progressively moved from being primarily reconnaissance tools to platforms capable of maintaining surveillance over an area for many hours and, in some cases, directly intervening against a target.

Predator and Reaper became symbols of that transformation.

Italy also entered this new phase. The use of Predator aircraft by the Air Force in international missions contributed to the establishment of the concept ISTAR: Intelligence, Surveillance, Target Acquisition and Reconnaissance.

War increasingly began long before the first shot: by collecting information, building a network of sensors, and tracking the target.

Intelligence and surveillance become weapons

September 11 also highlighted a fundamental problem: possessing information does not necessarily mean being able to connect it.

In the following years, integration between military intelligence, services, electronic surveillance, satellites, interception, and aerial reconnaissance increased enormously.

Among the first measures adopted by NATO after the attacks was precisely the increase in sharing of intelligence information between Allies.

That transformation continues today.

The modern battlefield has become a gigantic network in which sensors, drones, satellites, and ground units seek to reduce the time that passes between the discovery of a target and the possibility of striking it.

IED: a generation of soldiers learns a new threat

Afghanistan and Iraq produced another transformation.

Improvised Explosive Devices, IEDs, became one of the main threats to Western troops.

Armies responded by developing more heavily protected vehicles, electronic jamming systems, robots, new EOD equipment, and completely different procedures for column movement.

Force protection became a central discipline.

Many technologies today considered standard in military units were accelerated precisely by the experience accumulated on the roads of Afghanistan and Iraq.

The soldier becomes a network node

Individual equipment also changed.

Night vision devices, optics, lasers, communication systems, GPS, ballistic protection, and localization devices progressively spread to the lowest levels.

The Western soldier of 2026 is far more connected than his counterpart in 2001.

The trend is clear: to transform every squad and, progressively, every single military personnel into a sensor within the command and control network.

And it is precisely one of the deepest technological legacies of the wars that began after September 11.

Twenty years of counterinsurgency had a price, however

Not all consequences were positive.

For nearly twenty years, much of Western armies focused on counterinsurgency, counterterrorism, and stabilization operations.

The typical enemy was represented by small irregular formations equipped with light weapons, mortars, rockets, and improvised devices.

The war in Ukraine would later remind the West that a war between modern armies requires artillery again, air defense, electronic warfare, fortifications, large quantities of ammunition, and industrial capacity.

In 2026, armies are therefore experiencing a sort of synthesis between two eras.

From Afghanistan and Iraq they retain drones, intelligence, Special Forces, precision, and the ability to operate in small units. From conventional warfare they are recovering mass, artillery, air defense, and the capacity to sustain high-intensity combat.

From terrorism to multi-domain warfare

The very concept of threat has further expanded.

Cyberattacks, GPS interference, disinformation, sabotage, electronic warfare, and attacks on infrastructure are now part of the confrontation between States.

Security is today interpreted in a much broader way than in 2001 and includes threats that can develop simultaneously on the military, cyber, economic, informational, and infrastructural levels.

The evolution that began after September 11 has thus surpassed the very terrorism that had originated it.

Twenty-five years later

September 11, 2001 changed airports, intelligence, international politics, and internal security.

But it changed above all the way we fight.

It accelerated the rise of Special Forces, transformed drones into fundamental tools, imposed a new culture of intelligence, developed the capability to strike targets with precision from across the world, and forced Western armies to face for twenty years an enemy radically different from the one they had been prepared for during the Cold War.

Today the main threat has returned to include also confrontation between great powers and conventional warfare.

Yet much of the tools used on the 2026 battlefield still bears the imprint of what happened that morning.

Twenty-five years later, September 11 does not belong only to memory. It is still within the way armies think, organize themselves, and fight.

Sources

• NATO – Collective defence and Article 5
  https://www.nato.int/en/what-we-do/introduction-to-nato/collective-defence-and-article-5

• NATO – Invocation of Article 5 confirmed
  https://www.nato.int/en/news-and-events/articles/news/2001/10/02/invocation-of-article-5-confirmed

• U.S. Department of Defense – 9/11 Attack history
  https://history.defense.gov/DOD-DOW-History/Pentagon/9-11-Attack/

• Ministry of Defense – Enduring Freedom Operation
  https://www.difesa.it/operazionimilitari/op-int-concluse/marearabicoenduring-freedom/default/27060.html

• Air Force – Timeline of international missions
  https://www.aeronautica.difesa.it/2022/11/09/timeline-storica-le-missioni-internazionali/