Europe’s Defence Build-Up Is a Growth Boost With Inflation and Fiscal Risks

The economic message surrounding Europe’s rapid defence build-up is a trade-off, not a simple growth story. EU defence expenditure rose from about €218 billion in 2021 to €418 billion in 2025, equivalent to 2.2% of EU GDP. For the euro area, ECB analysis indicates that higher government spending should support real output, but the size, timing and distribution of the effects remain uncertain.

The central warning: more spending is not a free lunch

Defence purchases can increase demand for factories, engineers, technology and specialised goods. That can raise production in the short term, particularly where unused capacity is available. But a fast, simultaneous build-up across countries can also compete with civilian investment and consumption for workers, materials, energy and production capacity.

When supply expands more slowly than demand, the same fiscal impulse produces less additional real output and more pressure on prices and wages. That is why the ECB’s assessment treats the inflation effect as a risk to monitor rather than as a fixed result.

Growth should rise, but the multiplier is uncertain

The ECB’s multi-model assessment estimates an average government-spending output multiplier of 0.93 over a two-year horizon. In practical terms, the estimate is close to—but not exactly—a one-for-one effect, and the ECB emphasises substantial variation between models.

That distinction matters. A multiplier near one describes the estimated response of output over a defined period; it does not mean that every euro spent creates a permanent increase in national wealth. The result will depend on the speed of spending, the state of the economy, the type of equipment purchased and whether production takes place inside or outside Europe.

Recent Eurosystem projections incorporate defence and infrastructure-related fiscal stimulus as a support for euro-area growth, with the impact building over the projection horizon. Earlier ECB analysis likewise estimated that new defence measures would support growth in 2026–27 while having a limited baseline effect on inflation.

Why monetary policy has to look beyond the headline spending figure

For the ECB, the relevant question is not simply how much governments announce, but how spending affects demand, supply and inflation persistence.

A gradual increase in defence outlays may be absorbed with relatively limited price effects if firms can expand production and workers can move into the sectors receiving new orders. A sudden procurement surge, however, could expose bottlenecks in skilled labour, engineering, specialised materials and industrial inputs.

That creates two possible channels for monetary policy:

• A demand channel: stronger public spending supports output and may reduce the need for highly accommodative policy.
• A supply-capacity channel: shortages and persistent wage or price pressures could make inflation more durable and require a tighter policy stance than otherwise.

The ECB’s modelling points to a positive output effect and only a modest average inflation effect in the scenarios studied, but it also highlights significant uncertainty. Policy therefore cannot respond mechanically to the announcement of a defence target; it must follow actual disbursements, capacity constraints and realised inflation.

Fiscal effects will be uneven across Europe

The same defence programme can create very different fiscal pressures in different countries. Governments with stronger budgets may be able to increase spending without immediately squeezing other priorities. Highly indebted countries or those with limited fiscal room face a sharper choice between defence, civilian investment, public services and debt sustainability.

ECB analysis has considered a rise in defence spending from around 2% of GDP to 3.5% by 2029, corresponding to fiscal loosening of about 1.8% of GDP by that year in the scenario described. That is a euro-area-wide assumption, not a forecast that every member state will follow the same path or experience the same consequences.

The financing method also changes the transmission of the shock:

• Deficit financing can deliver a stronger immediate demand boost, but increases borrowing and future debt-service requirements.
• Tax financing can reduce the net demand impulse by drawing purchasing power from households or companies.
• Joint European financing can share costs across countries and make coordinated procurement easier, particularly when national fiscal capacities differ.

These are economic mechanisms rather than guarantees. Their effects depend on the timing of payments, the credibility of fiscal plans and the response of financial markets.

Where the money is spent may determine Europe’s payoff

Defence spending generates a larger domestic economic effect when European firms supply the equipment and services. The ECB’s Financial Stability Review notes that sourcing defence equipment within the EU would imply a higher fiscal multiplier.

By contrast, procurement from suppliers outside Europe can send part of the demand abroad. That may still provide military value, but it reduces the immediate boost to European production and limits the development of local industrial capacity.

Coordinated procurement, interoperable systems and expanded European production could therefore improve both the strategic and economic return. The benefit is not automatic: it depends on whether governments avoid duplication, invest effectively and build capacity quickly enough to meet demand.

The longer-term upside is possible, not assured

Defence research and development may produce wider productivity benefits when technologies spread into civilian applications. The ECB has also highlighted the scale of public funding requirements facing defence alongside Europe’s green and digital transitions.

Those potential spillovers should not be treated as a guaranteed return on military expenditure. They depend on procurement quality, research diffusion, private-sector adoption and whether defence investment complements rather than crowds out productive civilian projects.

Bottom line

The ECB’s message is best understood as conditional optimism. Europe’s defence build-up can support euro-area output, and current model estimates place the average two-year government-spending multiplier close to one. But the economic result will be less favourable if spending arrives faster than supply can respond, if too much procurement is sourced abroad or if national debt pressures restrict investment elsewhere.

For monetary policy, the key variables are the spending’s pace, composition and inflation pass-through. For governments, the central challenge is to strengthen defence without turning a necessary security response into an unmanaged demand shock or a source of deeper fiscal divergence.