The Alliance’s new spending commitment is strategically significant, but Europe cannot buy credible readiness with percentages alone. Fiscal space, production capacity and procurement discipline will determine whether the target produces usable forces.

NATO’s commitment to spend 5 per cent of gross domestic product on defence and security by 2035 has reset the political benchmark for European rearmament. The harder question facing leaders in Ankara is whether national budgets and defence industries can convert that promise into deployable capability.

Under the Alliance’s agreed framework, at least 3.5 per cent of GDP is intended for core military requirements, while up to 1.5 per cent can cover critical infrastructure, networks, civil preparedness, resilience, innovation and the defence industrial base.

That division is sensible. Modern deterrence depends on ports, railways, data networks, factories and civilian resilience as well as combat units. But a broad definition also creates room for accounting choices that raise reported expenditure without closing NATO’s most urgent capability gaps.

A target is not a force plan

Defence budgets matter because armies cannot train, equip or sustain themselves without predictable finance. Yet the same sum can produce very different outcomes depending on procurement, labour availability and industrial capacity.

Europe needs more air and missile defence, long-range fires, ammunition, drones, electronic warfare, logistics, strategic lift and secure command systems. It also needs trained personnel, spare parts and maintenance capacity. Buying a small number of high-profile platforms while leaving units short of munitions or technicians will not meet that requirement.

Defence Matters has argued that the Ankara summit is a test of European capacity rather than reassurance. The 5 per cent pledge will be credible only if annual national plans show which capability targets are being funded and when they will become operational.

Fiscal room varies sharply

The commitment lands unevenly across the Alliance. Germany has altered its constitutional borrowing framework and is sharply increasing defence expenditure. Poland and the Baltic states already spend at high levels because they perceive the Russian threat as immediate.

Other allies face more difficult arithmetic. Italy and France have high public debt; Spain has argued that it can meet assigned capabilities without adopting the full headline percentage. Governments also face demands for pensions, healthcare, climate investment and industrial support.

This does not make defence optional. It means the Alliance needs credible national trajectories rather than identical annual jumps. Spending that triggers domestic political reversal after two or three years would be less useful than a durable programme tied to agreed forces and procurement.

The EU can provide limited fiscal flexibility for defence and help aggregate demand, but it cannot eliminate national debt costs. Common financing may be appropriate for genuinely shared assets and industrial expansion, particularly where fragmented national orders prevent scale.

Industry cannot respond to slogans

European manufacturers need multi-year contracts before they invest in plants, tooling and skilled labour. Governments often announce demand while negotiating small batches, national workshare and bespoke variants. That behaviour lengthens delivery times and raises unit costs.

The industrial constraint is particularly severe for air-defence interceptors, rocket motors, energetic materials and artillery ammunition. Supply chains rely on specialised components that cannot be expanded overnight. Production also requires secure energy, transport and access to critical minerals.

The 1.5 per cent security category could help if it finances resilient factories, military mobility and protected infrastructure. It will be less valuable if states simply relabel existing civilian expenditure to reach the target.

Ukraine is the immediate test

Support for Ukraine should not be treated as separate from NATO readiness. Kyiv’s demand for air defence, ammunition and drones exposes the same production shortages that would affect allied forces in a wider conflict.

European governments sometimes frame replenishing national stockpiles and supplying Ukraine as competing objectives. The durable answer is expanded output. Reducing support to preserve inadequate inventories leaves the industrial bottleneck unresolved and gives Russia time to rebuild.

Ukraine also provides operational knowledge that procurement systems struggle to absorb. Rapid software updates, dispersed manufacturing and low-cost interceptors are now central to survivability. A larger budget that remains locked into peacetime acquisition cycles will not capture those lessons.

Ankara must demand measurable delivery

The summit should therefore make the spending pledge auditable in military terms. Allies need annual plans for formations, readiness levels, stockpiles, infrastructure and industrial output. NATO should identify where national programmes duplicate one another and where joint procurement could accelerate delivery.

Five per cent is politically powerful because it signals that the old European security model has ended. It is not, by itself, evidence that the replacement is functioning.

The measure of success will be whether Europe can field more ready forces, sustain Ukraine, protect its rear areas and replace losses during a prolonged conflict. If the target produces those outcomes, it will strengthen deterrence. If it produces creative accounting and fragmented fleets, the Alliance will have spent more without becoming secure enough.