In Spain, Europe staged a battle to test its future

ZARAGOZA – Across a dust-choked plain on the city's outskirts, 2,600 soldiers from 13 nations fought through a war that didn't exist. The city was fictional. The insurgency was scripted. The helicopters, explosions and split-second decisions were not.

The scenario centered on Seglia, a fictional state where security had deteriorated sharply since the summer of 2025 after a self-declared autonomous administration emerged with the backing of an armed insurgent group. When its president appealed for European military assistance, the European Union activated its Rapid Deployment Capacity. Tanks, helicopters, fighter jets, electronic warfare units and intelligence teams converged on the San Gregorio training area, where the bloc was putting its military ambitions to the test in MILEX26, one of its largest live exercises yet.

For the European Union, it was a test of something it has long struggled to prove: whether it can move fast enough to matter in a real crisis.

On the ground, events unfolded much as they might in a real operation. An insurgent ambush on a battalion convoy triggered a combined-arms response. Once enemy positions were identified, EU forces launched an air assault, evacuated a casualty and cleared explosives from the withdrawal route. Then one of the four tanks failed to exit as scheduled, forcing commanders to improvise.

“This is reality, and you need to train for it,” said Lt. Gen. Michiel van der Laan, director of the EU’s Military Planning and Conduct Capability and commanding officer of the exercise. “Because we cannot say we are not going to the field.”

Training together, he added, isn't just preparation but the price of ambition. “We want to be world champions. Then we need to be prepared to win.”

Beyond the June exercise, the debate in Brussels has shifted. The question is no longer whether Europe should act independently of NATO, but what role remains for EU military structures as the Alliance itself becomes more European in practice.

That evolution is forcing a reckoning with what the Rapid Deployment Capacity and the MPCC are actually for, whether they can succeed were earlier initiatives failed — and how they fit into what some officials have already dubbed NATO 3.0.

The making of the EU battlegroups

The force tested at MILEX26 has its roots in a more modest concept: the European battlegroups.

Created in 2004 and fully operational from 2007, the battlegroups consisted of multinational formations of around 1,500 troops, mostly focused on land operations. Participation was voluntary, with willing member states rotating through six-month standby periods.

Over time, the EU assembled 18 regional groups, including the Swedish-led Nordic Battlegroup with non-EU Norway, the Spanish-Italian Amphibious Battlegroup, and the Polish-led Visegrad Battlegroup.

But in their two decades of existence, they were never deployed. Not even during the chaotic evacuation from Afghanistan in 2021.

Critics saw the battlegroups as victims of the EU's decision-making process: a force that existed on paper but never enjoyed the political consensus required for deployment. Others pointed to the lack of a unified and agile command-and-control structure. The model relied heavily on a one-size-fits-all concept, as well as on member state solidarity. With most EU countries also committed to NATO, governments faced competing demands for the same limited troops and funding.

But for Javi López (S&D, ES), vice president of the European Parliament, the battlegroups’ languishing had a silver lining, providing key insights for future EU defense planning.

The EU appears to have taken those lessons on board, while Russia’s full-scale invasion of Ukraine in 2022 also accelerated momentum to finalize existing plans. The battlegroups evolved into the Rapid Deployment Capacity, expanding to at least 5,000 troops with a more flexible structure adapted to different scenarios, more integrated command-and-control capabilities, as well as and intelligence, surveillance and reconnaissance systems.

Designed to deploy within 10 days, the RDC can field troops for evacuation and disaster relief, conflict prevention and rescue operations across land, air, maritime and cyber domains. The RDC’s missions are also more clearly defined than those of the battlegroups, and the standby period has been extended to one year.

Today, the Brussels-based Military Planning and Conduct Capability serves as the designated operational headquarters.

The EU has also sought to remove financial barriers that hampered the battlegroups. Instead of relying on national budgets, member states can now draw on the €17 billion European Peace Facility — an EU instrument that supports military and defense operations — to cover a significant share of training, preparation and deployment-related costs.

RDC’s missing pieces

The RDC marks a big leap forward from the idle battlegroups, experts agree. But whether it can become a credible military instrument and function on a battlefield will ultimately depend on more than one successful exercise.

The biggest obstacle may also be the oldest. Sending the RDC into action still requires the unanimous approval of all 27 member states in the Council of the European Union, leaving the force vulnerable to political deadlock as threat perceptions differ between governments.

“What remains to be addressed is the unanimity requirement,” López said.

“As long as the EU Common Security and Defence Policy remains an intergovernmental domain, any deployment will be dependent on political will,” said Yf Reykers, associate professor of International Relations at Maastricht University. “In a Union of 27, this is and will remain a challenge.”

For López, the next challenge is capability. The EU remains dependent on NATO and national militaries for strategic enablers like airlift, satellite intelligence and integrated air defense. Instruments like the nearly €8 billion European Defence Fund and the €1.5 billion European Defence Industrial Programme narrows the gap, he said, but investment levels remain modest relative to the scale of the challenge.

Reykers also sees the expansion to a force of up to 5,000 personnel as only a limited quantitative improvement. The key question, he argues, is whether the RDC can assemble different force packages depending on mission and geography. The balance of land, air, maritime and special operations forces — alongside strategic enablers — would vary significantly from one operation to another.

In practice, maintaining a 5,000-troop force package on high alert year-round would require “a considerably higher” pool of personnel, he added. While some units remain on standby, others would be preparing to rotate in, while others recover from previous deployments and training cycles.

Yet even a more capable force may struggle to deploy if governments cannot agree on when to use it. According to Christoph Meyer, professor of European and International Politics at King’s College London, crises in places such as Mali and the Central African Republic are still largely viewed through national rather than collective European lenses.

“It’s hard to see a scenario where the ‘stars will align’ to lead to the launch of the first mission,” he said, pointing to competing demands in the current political climate.

If that makes a first deployment unlikely, Reykers added that deciding whether the force is even fit for purpose first requires an agreement on what the RDC is actually expected to do. That, he said, is only possible if member states share an understanding of where NATO is heading and what that means for the EU’s much smaller command structure.

Europe's military endgame

As anxieties grow over reduced U.S. military presence in Europe, calls for a standing European military force has made its back on the political agenda. Earlier this year, EU Defence Commissioner Andrius Kubilius argued that the long-debated idea championed by figures such as Jean-Claude Juncker, Emmanuel Macron and Angela Merkel deserves renewed consideration as Washington’s security commitments becomes more uncertain.

Drawing on an analysis by the Washington-based Center for Strategic and International Studies, the former Lithuanian prime minister has proposed a standing pan-European force of at least 100,000 troops, separate from national armies and designed to complement U.S. forces stationed in Europe.

Spanish Prime Minister Pedro Sánchez has also argued that a European army operating under a single flag and pursuing common objectives is “the only way” to guarantee lasting peace on the continent.

For now, however, those ideas remain largely confined to the drawing board. The notion of the RDC as the nucleus of a future European army remains largely theoretical.

“It is ultimately a political question,” said General Seán Clancy, chairman of the European Union Military Committee. “The rapid deployment capacity has been established with a very clear statement in terms of level of ambition.”

But he added that the RDC is committed to defending EU countries and allow them to operate together when required under the Common Security and Defence Policy.

Reykers believes the RDC will remain focused on the EU’s immediate neighborhood, and be increasingly viewed as a tool for protecting the bloc's borders and interests.

“The EU needs to walk before it can run,” Meyer said. “It's better to lower expectations and then, perhaps, have operational successes than to find out that calls for the EU RDC are not answered, or that it fails to deliver in the field.”

In defense and deterrence, he added, credibility is essential. The EU must be able to send clear signals, demonstrate the ability to escalate when necessary and continue to exercise jointly while preparing for worst-case scenarios.

For tasks that go beyond crisis management and prevention, however, Meyer argues Europe already has a dedicated military organization: NATO. If the Alliance cannot be reformed to meet future challenges, policymakers have to consider a different institutional design. Until then, he said, we’re stuck with coalitions of the willing.

Sign up to The Parliament's weekly newsletter

Every Friday our editorial team goes behind the headlines to offer insight and analysis on the key stories driving the EU agenda. Subscribe for free here.