Europe’s defense debate is missing the hardest question

For much of the past year, European leaders have been engaged in a renewed debate about “strategic autonomy.” From Brussels to Paris, policymakers are discussing whether Europe should build a more independent defense capability, sometimes framed in terms of a future European army. The conversation has gained urgency as the US continues its long-signaled strategic pivot toward the Indo-Pacific and asks European allies to shoulder a greater share of their own security.

Yet this debate is missing the most difficult question. The real challenge is not institutional design, procurement budgets or command structures. It is whether European societies are politically prepared to sustain the human cost of modern warfare.

The war in Ukraine has offered a sobering reminder of what high-intensity conflict between industrial powers actually looks like. According to Western intelligence estimates, Russia has suffered well over 300,000 casualties since the full-scale invasion began in 2022. Ukrainian casualties are also extremely high. While exact figures remain contested, the losses run into the hundreds of thousands.

These numbers are not unusual by historical standards. They are, however, politically extraordinary for modern European democracies. The US lost about 58,000 troops during the entire Vietnam War, a figure that produced years of domestic political upheaval. The UK lost about 456 personnel during the 20-year campaign in Afghanistan, which itself generated sustained political scrutiny.

By comparison, the daily casualty rates in the Ukraine war often exceed what Western societies experienced during entire months of their most recent conflicts.

This reality exposes a fundamental tension at the heart of Europe’s defense debate. Military capability is not simply a function of budgets and equipment. It ultimately depends on political legitimacy and the willingness of citizens to accept the costs of war.

Across Europe, defense spending has increased significantly since Russia’s invasion of Ukraine. NATO members collectively spent more than $1.3 trillion on defense in 2024. European NATO members alone spent more than $380 billion, the highest level in decades. Germany has established a €100 billion ($115 billion) special defense fund, while Poland is planning to spend about 4 percent of gross domestic product on defense, one of the highest levels in the alliance.

Military capability ultimately depends on political legitimacy and the willingness of citizens to accept the costs of war. 

Dr. Azeem Ibrahim

These investments are necessary and long overdue. For decades, many European states allowed their armed forces to atrophy under the assumption that large-scale war on the continent had become unthinkable. Rebuilding military capability will take years, if not decades.

But financial commitments alone cannot solve the deeper political problem. In democracies, public opinion ultimately shapes military strategy. Casualties must be explained, justified and politically sustained. Governments cannot simply absorb losses indefinitely without facing electoral consequences.

This is where the idea of a supranational European army runs into profound difficulties. Defense policy is inseparable from national sovereignty because it involves the decision to risk citizens’ lives. While European states may cooperate extensively on procurement and logistics, the final decision to send troops into combat remains a national political choice.

The EU already struggles to maintain coherence on foreign policy. Member states frequently disagree on sanctions, diplomatic strategy and relations with major powers such as China. Expecting these same governments to agree on the deployment of a unified military force in high-casualty conflicts stretches political credibility.

Democratic accountability further complicates matters. If European troops were deployed under a centralized EU command and suffered significant casualties, who would ultimately be responsible? National voters would expect answers from their own governments, yet the strategic decisions might have been made in Brussels by institutions that voters cannot directly remove from office.

This accountability gap is not a theoretical problem. It reflects the reality that military legitimacy still rests overwhelmingly with national political systems. Citizens expect their elected leaders, not distant bureaucracies, to make life-and-death decisions about war.

The manpower question also looms large. Many European armed forces face chronic recruitment shortages. Germany’s Bundeswehr has struggled for years to meet its personnel targets. Britain’s armed forces have fallen to their smallest size since the Napoleonic era. France maintains a capable military but its active personnel total remains modest relative to the scale of potential continental threats.

Citizens expect their elected leaders, not distant bureaucracies, to make life-and-death decisions about war. 

Dr. Azeem Ibrahim

Even if European defense budgets rise substantially, rebuilding large armies in societies that have grown accustomed to peace will be politically difficult. Conscription has largely disappeared across Western Europe and reintroducing it would provoke intense political debate.

All of this suggests that Europe’s defense future will remain anchored in NATO rather than in an entirely new institutional framework. NATO provides something that no alternative structure currently can: an integrated command system, decades of operational experience and, crucially, the strategic umbrella of the US.

America still accounts for roughly two-thirds of NATO’s total defense spending. Its logistical capacity, intelligence infrastructure and strategic nuclear deterrent remain central to the alliance’s credibility. Even as Washington encourages Europeans to take greater responsibility, it is unlikely to abandon the alliance that has underpinned transatlantic security for more than 70 years.

None of this means that Europe should remain passive. On the contrary, European states must continue strengthening their military capabilities, investing in defense industries and improving operational coordination. The war in Ukraine has demonstrated the importance of ammunition stockpiles, air defense systems and resilient supply chains.

But strategic realism requires recognizing that defense is ultimately a political project as much as a military one. Institutions can be built. Budgets can be increased. Weapons can be procured. What cannot be easily manufactured is the political consensus required to sustain the costs of major war.

Until European leaders confront that reality directly, the debate about a European army will remain largely theoretical.

For now, NATO remains the only structure capable of providing credible collective defense on the continent. Strengthening that alliance, rather than attempting to replace it, remains the most practical path forward for European security.

• Dr. Azeem Ibrahim is the director of special initiatives at the Newlines Institute for Strategy and Policy in Washington. X: @AzeemIbrahim