Sword 26: Cyber Defenders Train in Estonia, Secure Critical Infrastructure

From the outside, the Cyber Range 14 building in downtown Tallinn, Estonia, appears quiet, unassuming and pristine. Inside, no weapons are firing, no smell of gasoline or gunpowder hangs in the air. But the absence of traditional battlefield signs does not make the mission inside any less important - in many ways, it makes it even more so.

Soldiers assigned to Information Defense Company, Multi-Domain Command - Europe, alongside soldiers assigned to the Maryland Army National Guard's 169th Cyber Protection Team, quietly trained to defend the networks that modern societies rely on daily. And, if they succeed, most people will never even know it happened.

The training, conducted May 17-21, centered on Cyber Range 14, a cyber training facility in Tallinn where U.S. cyber defenders worked through a realistic critical infrastructure defense scenario. For this iteration of the training, members of the Estonian Defense Forces served as the opposing force, or red team, attempting to infiltrate simulated power and rail networks from distributed locations across the city.

On the other side of the exercise, IDCO and 169th CPT soldiers served as the blue team. Their mission was to move through the network, identify suspicious activity, research anomalies and secure vulnerabilities before the red team could exploit them.

The Cyber Range is a part of Sword 26, U.S. Army Europe and Africa's premier annual exercise series, which took place across eight countries in the High North and Baltic regions. Formerly known as Defender, Sword 26 validates NATO regional defense plans and operationalizes the Eastern Flank Deterrence Initiative.

While Sword 26 includes large-scale movement, maneuver and training across multiple countries, the work at Cyber Range 14 focused on a quieter, but equally critical, piece of modern defense: protecting the networks and infrastructure that enable allied forces to communicate, move and sustain operations.

"It's not enough to know how to defend your own network in isolation," said Army Maj. Marissa Robbins, blue team leader and team lead for the 169th Cyber Protection Team. "In a real-world environment, we have to be able to work with our allies, understand how they operate and defend shared systems before an adversary can use them against us."

It was not the kind of fight marked by smoke, noise or heavy equipment. Instead, it unfolded through monitors, code, network traffic and the quiet concentration of cyber defenders working to identify the threat before it could affect the network.

The scenario reflected one of the central challenges of modern warfare: protecting the systems that make military operations possible and keep civilian life moving. Power grids, rail networks and communications systems are no longer separate from the battlefield. If an adversary can disrupt or control those networks, they can affect civilian populations, delay military movements and create uncertainty long before conventional forces ever meet.

Within that greater effort, cyber defense is a critical part of making the Eastern Flank Deterrence Initiative more than a concept. Defending the digital systems that support movement, communication and daily life is essential to maintaining readiness and resilience along NATO's eastern flank.

The exercise also reinforced the importance of training with allies before a real-world crisis demands it. Estonia's position on NATO's eastern flank gives the training added relevance, but the exercise's value extends beyond geography. Bringing U.S. soldiers, National Guard cyber professionals and Estonian Defense Forces together allowed each organization to share experiences, compare tactics, techniques and procedures and learn how their partners approach the same problem set.

Those exchanges matter. Cyber defense is built on technical skill, but it also depends on trust, communication and familiarity. In a crisis, the first conversation between allies should not be an introduction.

By working through the scenario together, the teams gained a better understanding of each other's standard operating procedures and decision-making processes. They also saw how different organizations bring distinct strengths to the same fight - whether through technical expertise, an operational perspective or experience defending networks in a challenging security environment.

For the soldiers involved, the range offered more than a simulated attack. It provided a chance to rehearse the kind of defense that is often invisible when it succeeds; a protected network rarely makes headlines. A stopped intrusion may never be noticed outside the room, but that quiet success is exactly the point.

Cyber may not look like the traditional image of warfare - there are no armored vehicles moving across a training area, no artillery rounds shaking the ground, no visible front line - but without secure networks, the forces that depend on them may struggle to communicate, move, sustain and coordinate across the battlefield.

The Cyber Range 14 battlefield was quiet. The mission was not.