Bruxelles – European defence spending is rising at a remarkable pace. According to the European Defence Agency (EDA), EU Member States spent €418 billion on defence in 2025, equivalent to 2.2 per cent of GDP. That figure is expected to continue rising significantly over the coming years.
The increase is important. Russia’s war against Ukraine has forced European governments to confront military weaknesses accumulated over decades, while the changing US role in European security has increased pressure on Europe to assume greater responsibility for its own defence.
But Europe now faces a different problem. The question is no longer simply: are European countries spending enough on defence?
More than ever, it is: what kind of defence is all that money actually building?
The EDA’s latest assessment points towards the problem. Spending is rising and procurement is accelerating, yet serious capability gaps remain. Much of Europe’s defence investment also continues to be organised nationally rather than collectively.
Europe can therefore increase defence spending without necessarily increasing European defence.
Spending more is not the same as building capability
For years, European defence debates have revolved around how much governments spend.
That made sense.
European armed forces suffered from decades of underinvestment, depleted ammunition stocks and defence industries structured around relatively modest peacetime demand. Reversing that decline inevitably requires money.
That process is now under way. But expenditure is an input. Military capability is the outcome. And the two should not be confused.
A country can purchase additional tanks, artillery, aircraft or air-defence systems and undoubtedly strengthen its national armed forces. The more difficult question is whether those investments also contribute to a force capable of operating effectively with its European allies.
Contemporary warfare depends on considerably more than the number of weapons available.
Forces have to communicate. Ammunition and spare parts have to be available. Equipment has to be maintained. Intelligence has to move between commands. Air-defence systems need to exchange information. Reinforcements need to cross borders and reach the battlefield. And weapons destroyed or expended during combat have to be replaced.
A military therefore does not possess a capability simply because it owns a weapon. It possesses a capability when it can deploy, operate, supply, maintain and regenerate it.
That distinction should increasingly sit at the centre of Europe’s defence debate.
Twenty-seven larger inventories do not create one defence system
This is where Europe’s current spending surge becomes more complicated.
National governments still make most procurement decisions according to national requirements, budgets and industrial priorities.
The result is that 27 countries can simultaneously increase defence expenditure while continuing to develop different procurement programmes, supply chains, maintenance systems and operational requirements.
EDA data for 2025 show that collaborative procurement accounted for only 24 per cent of defence equipment procurement expenditure, below the Agency’s longstanding 35 per cent collective benchmark.
That matters because fragmentation has consequences beyond the initial purchase. Different systems create different requirements for training, ammunition, spare parts, maintenance and logistics. Those differences then have to be managed when national forces are expected to operate together.
Military mobility illustrates the problem.
It is not enough for Europe to possess heavy forces in one part of the continent if moving them rapidly to another remains difficult. Roads, railways, bridges, border procedures and military logistics all become part of the military capability.
The same principle applies to air defence. Buying additional launchers does not automatically create an integrated European air-defence architecture. Sensors, command-and-control systems and interceptor stocks have to work together around them.
More equipment can strengthen Europe.
But more equipment and more integration are not the same thing.
Ukraine has demonstrated what capability actually means
The war in Ukraine has provided Europe with a particularly stark demonstration of this distinction.
Individual weapons have repeatedly dominated discussion of Western military assistance.
But battlefield effectiveness has depended on the systems surrounding them.
A Patriot battery without sufficient interceptors cannot provide sustained air defence. A tank without maintenance, ammunition and logistics cannot remain in combat. A long-range strike weapon requires intelligence and targeting, while the ability to sustain its use depends on industrial capacity to manufacture replacements.
Ukraine has also demonstrated that those requirements are constantly changing.
Weapons are modified following battlefield experience. Electronic-warfare systems adapt. Drone frequencies change. New interceptors are developed against new threats. Production lines then have to incorporate those lessons quickly enough for adaptation to matter on the battlefield.
The lesson is straightforward. Military capability is a system, not an inventory.
The EDA itself increasingly recognises Ukraine’s relevance to this discussion. Its Annual Defence Readiness Report identifies Ukrainian battlefield experience, technological innovation and defence-industrial capability as potential contributors to improving European readiness.
Europe therefore has more to learn from Ukraine than which particular weapons perform well. The deeper lesson concerns how military capability is generated, adapted and sustained.
Europe risks locking fragmentation in
There is another reason why the current moment matters. Major defence procurement decisions have extremely long consequences.
A government buying a new aircraft, armoured vehicle or air-defence system is not simply making a purchase for this year’s defence budget.
It is potentially choosing decades of training, maintenance, ammunition requirements, upgrades, infrastructure and industrial relationships.
That means Europe’s current rearmament could shape the structure of European defence long after the immediate political pressure to spend has passed.
If governments use rising budgets predominantly to expand separate national procurement programmes, today’s spending surge could begin to show cracks and fragmentation rather than reduce it.
Integration afterwards becomes considerably harder. Europe therefore faces an unusual window. Defence budgets are rising. Production capacity is expanding. Governments are making procurement decisions that may define European forces into the 2040s and beyond.
The important matter is whether coordination happens before those decisions become locked in.
The next defence metric should be readiness
None of this means Europe should spend less on defence.
The capability gaps identified by EDA demonstrate why additional investment remains necessary. But the success of European rearmament cannot ultimately be judged by expenditure alone. Percentages of GDP are politically useful because they provide a simple way of comparing national effort.
They tell us much less about whether a military can actually fight. The next phase of the debate therefore needs harder measures.
Can European forces move rapidly across the continent?
Can their command systems communicate?
Can national air-defence networks exchange information?
Are sufficient ammunition and spare parts available?
Can industry manufacture missiles and shells quickly enough to replace wartime expenditure?
And when equipment is damaged or destroyed, how rapidly can Europe regenerate combat power?
Those questions are considerably less straightforward than calculating a percentage of GDP. They are also much closer to what determines military effectiveness.
From spending to defence
Europe needed to spend more on defence. That argument has largely been won. The more difficult question now is what hundreds of billions of euros in additional expenditure actually produce.
Twenty-seven countries buying more weapons will create larger national inventories. It will not automatically create a coherent European defence capability.
And because the procurement decisions being made today will shape European armed forces for decades, the cost of getting that distinction wrong could last considerably longer than the current spending cycle.
The next phase of European rearmament therefore cannot simply be about spending more. It has to be about making that spending work together.
English version by the Translation Service of Withub
