Europe Needs an Army | Foreign Affairs

The transatlantic alliance is on the ropes. Since the end of World War II, American power has underwritten European unification and integration—arguably Washington’s greatest foreign policy accomplishment. But the Trump administration has made clear that the United States is no longer interested in acting as Europe’s security guarantor. It has threatened to seize the territory of a NATO member, reduced funding to Ukraine, aggressively imposed tariffs on European allies, and, in its 2025 National Security Strategy, called for “cultivating resistance to Europe’s current trajectory.” The message could not be clearer: the continent can no longer rely on the United States to defend it. For the first time in eight decades, Europe stands alone.

European states now find themselves vulnerable to Russian aggression. Should Moscow turn its attention beyond Ukraine and rebuild its war machine, it could quickly threaten eastern Europe. Such a danger should spur European leaders to embark on a bold new course of action to solidify their defenses. But there has been no such revolution in European military affairs. Although NATO countries have agreed to increase defense spending to 3.5 percent of GDP by 2035, they cannot spend their way to security. The issue is structural, not financial. European militaries are not set up to defend the continent without the United States.

European leaders are keenly aware of their security dependence but in denial about what must be done. The biggest stumbling block is the belief that defense is a national responsibility rather than a European one. Individual governments across Europe want to retain sovereignty over their militaries and have been reluctant to Europeanize their defense efforts. But this focus on national sovereignty overlooks a deeper reality: European countries are not and have not been sovereign in defense since the end of World War II. They have relied on the United States, a foreign power, to protect them. Now, with that foreign power abandoning them, the most effective way European states can defend themselves without Washington’s backing is to integrate their defense efforts. They need to do what they would in any other crisis: activate the European Union. It is time for the EU to become Europe’s Pentagon.

PILLAR OF STRENGTH

This is not the first time that a defenseless Europe has faced a United States wanting to retreat to its own shores. In the late 1940s, Washington found itself trapped: its overriding priority was to bring American troops home from World War II, but Western European countries were still too weak to defend themselves, and the Soviet threat was too severe for Americans to leave without risking that the continent would fall under communist rule.

Washington’s preferred solution was not NATO, which, according to the historian Sten Rynning, U.S. officials considered a “holding measure until Europe’s condition improved.” The larger goal was to build a united Europe into a “third force” that could counter the Soviet Union without needing to rely on the United States. The “first step in the federation of Europe,” as French Foreign Minister Robert Schuman proposed in an address in May 1950, was the establishment of the European Coal and Steel Community, which would reconcile France and Germany and integrate the industries necessary to wage war. Reconciliation was the starting point, but the ultimate aim was to revitalize European power. This project eventually became the European Community, the precursor to the European Union.

When North Korea invaded South Korea in June 1950, just a month after Schuman’s speech, the United States was suddenly pulled into a war in the Indo-Pacific. With U.S. forces stretched thin, the prospect of a Soviet invasion of Europe became very real. In response, and to accelerate Europe’s federation, French Prime Minister René Pleven proposed the creation of a European army. If Western Europe were strong enough to deter the Soviet Union, the argument went, it would allow the United States to pull back its military presence from the continent. With strong backing from the Truman administration and U.S. General Dwight Eisenhower, then NATO’s supreme allied commander, six Western European countries—Belgium, France, Germany, Italy, Luxembourg, and the Netherlands—signed a treaty in May 1952 to create a common army with a shared budget, governing council, consultative assembly, and court. But the plan never took off. Despite the idea’s French origins, the French parliament blocked ratification of the treaty in 1954 after General Charles de Gaulle decried the prospect of ceding French sovereignty. Much to the chagrin of both the Gaullists and the Eisenhower administration, U.S. troops remained in Europe indefinitely.

The EU must become Europe’s Pentagon.

The result was that Europe never needed to federate militarily. NATO gave European countries the illusion of sovereign control over national defense. Officially, all NATO states had an equal say in the North Atlantic Council, the alliance’s decision-making body, and maintained their own independent militaries. But the United States was the one that called the shots. If a war erupted, every European leader knew the United States would handle it.

After the Iron Curtain collapsed, the European Community transitioned into the European Union. The 1993 Maastricht Treaty, signed by 12 European states, established the Common Foreign and Security Policy, a new pillar dedicated to shared defense. By that point, however, the United States had decided it did not want to leave Europe. U.S. Secretary of State Madeleine Albright insisted in 1998 that there should be no “decoupling” or “duplication” between the EU and NATO because it would undermine the primacy of the United States in the transatlantic alliance. The EU was not to do defense; that was Washington’s job. The EU’s Common Foreign and Security Policy has thus largely sat dormant.

FLYING SOLO

Europe is back where it was in the early 1950s, facing a predatory Russia while the United States rushes for the exits. Europe must now assume that it has to defend itself without American support. This challenge is surmountable but requires more than merely boosting defense budgets. The continent is home to roughly 30 distinct militaries, which operate at varying levels of readiness and capability and use their own equipment. If Russia were to amass troops on the border of a Baltic state, all of Europe’s disparate forces would need to rapidly deploy and seamlessly fight together.

In theory, NATO coordinates these moving parts. But a NATO without the United States would be a hollow shell. When the alliance mobilized European forces in Afghanistan, the Balkans, and Libya, for instance, U.S. military prowess masked the inadequacies of those European missions. Europe’s armies lack sufficient materiel, such as airtankers, airlifters, and advanced surveillance and targeting technology. The capacity gap is baked in: European militaries were designed to serve as auxiliaries in a U.S.-led NATO war effort.

Only 19 percent of Europeans are confident that their national armies could defend them.

A U.S. retreat most concerns the European states bordering Russia—understandably so. Frontline states such as Estonia, Latvia, Lithuania, and Poland have pleaded for other European states to spend more, but marginal increases in national defense spending will not turn their militaries into a cohesive fighting force. It is also unlikely that most European states will meet their pledge to NATO to raise defense spending to 3.5 percent of GDP because such policies are often unpopular domestically. Many citizens of nonfrontline states see their national militaries as tangential to deterring Russia and do not believe they are up to the task. A pan-European poll conducted by Le Grand Continent in early 2025 showed that although a majority feared the outbreak of a conflict, only 19 percent of respondents were confident that their national armies could defend them—compared with 60 percent who felt confident in a hypothetical common European army. Europeans don’t want good money going to bad militaries.

Nor can any of Europe’s traditional powers effectively oppose Russian aggression on their own. France and the United Kingdom have major budget deficits, leaving them low on funds to ramp up already overstretched militaries. Moreover, years of austerity have ground down the British army: the United Kingdom would struggle to deploy even 25,000 troops to eastern Europe today. German Chancellor Friedrich Merz has begun investing massively in defense, and Berlin has the scale to serve as Europe’s military backbone, but the country’s postwar history of pacifism and aversion to military power makes relying on a German military revival a risky bet.

As a result, Europeans have increasingly embraced ad hoc regional groupings. Despite decades of decrying any duplication with NATO, a flurry of minilateral frameworks have emerged that do just that. The Joint Expeditionary Force, a British-led military partnership designed for rapid reaction to crises, has its own command headquarters in London. As does the French-led “coalition of the willing” for Ukraine, in Paris. Nordic states are also increasingly integrating their military efforts. These arrangements are useful, but not if they sap the drive for a larger collective European effort.

ARMY OF ADMINISTRATORS

The European Union—with its 450 million people and an economy roughly the size of China’s—has the size, scale, and wealth to defend itself, but it is failing to leverage its advantages. Europeans need to relinquish the primacy of national sovereignty and integrate their efforts. The most pragmatic and effective means of achieving European collective security is by empowering the European Union on defense.

European leaders tend to blame “Brussels bureaucrats” when something—anything—goes wrong. The EU is far from perfect, of course. But at its core, it is Europe’s vessel for pooling sovereignty and uniting Europe. It has decades of experience integrating Europe’s commercial and industrial sectors and harmonizing policy. Unlike individual state governments, the EU focuses on advancing common interests rather than just national ones.

The EU is also where Europe turns in times of crisis, and it has proved it can act. When saboteurs destroyed the Nord Stream gas pipelines in 2022 and Europe was plunged into an energy crisis, for instance, the EU stepped in to coordinate energy policy. When COVID-19 struck in 2020, the EU purchased hundreds of millions of vaccines for the citizens of its member states, even though health policy was strictly a “national competency.” And following the 2015 migration crisis, when more than a million refugees sought to enter Europe, Brussels recruited a border service of 10,000 armed guards. The EU functions as Europeans need—and now they need it for defense.

Europeans should take over top NATO posts, including supreme allied commander.

More important, European citizens want the EU to do defense. The EU is the continent’s most trusted governing institution, more so than any member state. According to a 2025 Eurobarometer survey, roughly 80 percent of Europeans worry about the EU’s security over the next five years and support a common defense and security policy. The center-right European People’s Party, the largest party in the European Parliament, supported a pan-European military during its successful 2024 election campaign. Rob Jetten, the incoming Dutch prime minister, said during his October 2025 campaign that he wanted to give “the EU the power and the resources to do what citizens all across Europe are asking it to do: defend our territory against Putin’s aggression.”

The main obstacle is bureaucratic, not political. Europe’s national defense ministries deeply oppose ceding control. If Brussels handled military acquisitions, the EU’s 27 defense ministries would no longer need their own bloated procurement offices. National defense companies would lose their privileged contracts. In the 1980s, problems of national bureaucratic bloat, corporate state capture, and protectionism led British Prime Minister Margaret Thatcher to champion the Single European Act to integrate the European market, which led to major efficiency gains and cost savings across the continent in exchange for strengthening Brussels. The same gains—and the same tradeoff—would occur in the defense industry from EU integration today.

Few European political leaders today have called for such a trade. But with more money needed for the military, there will be less for social spending initiatives. Are European leaders prepared to trade butter for guns just to appease their defense ministers? The EU would need a sizable defense budget, funded through member-state contributions, joint borrowing, or the removal of restrictions on Brussels’s ability to raise revenue. But Europe does not need to spend as much as the United States does on its military to deter Russia. Pooling funds for joint procurement would spread the spending burden across the continent, strengthen Europe’s defense industrial base, and help streamline Europe’s militaries. According to a study from the think tank Bruegel, it would create enormous economies of scale that could reduce rearmament costs by half.

GROUP EFFORT

Empowering the EU on defense would not spell the end of NATO or national militaries. The EU’s focus would be on funding and organizing European troops—that is, serving as Europe’s Pentagon. Brussels would merge many of the functions of national procurement offices and manage major acquisitions, as well as integrate and regulate its 27 member states’ defense industrial sectors. NATO, ideally, would remain Europe’s combatant command, coordinating and executing missions. The alliance, however, should be increasingly Europeanized. With U.S. interest in NATO declining, Europeans should propose to take over top posts, including supreme allied commander, which has always been held by an American. National militaries, especially those of frontline states and traditional military powers, would still serve as the crux of Europe’s defense. But these forces would be Europeanized and augmented by the EU.

Brussels could also create a rapid-response force made up of troops from nonfrontline states. Italy and Spain could lead the force because each has a standing army more than 100,000 strong. If they stationed troops to the east of the Pyrenees and north of the Alps and integrated them with other small nonfrontline armies, the EU could form a permanent force able to react quickly to a Russian attack, filling the role imagined for U.S. ground forces in Europe. Since NATO and EU membership already obligates European militaries to fight together in war, it makes sense to integrate now, before war hits. Mobilizing troops into a rapid-response force would also give all countries an opportunity to demonstrate solidarity with frontline states and do more for their security. The EU would manage, fund, and equip this force but could make it available for NATO to command in the event of a war, as originally envisioned in the treaty for a common army signed in 1952.

Roughly 80 percent of Europeans support a common defense and security policy.

Integrating defense also requires integrating European foreign policy. Europe needs to be able speak with one voice—something the proliferation of ad hoc regional groupings complicates. One solution, put forth last month by Andrius Kubilius, the European commissioner for defense and space, is a European Security Council comprising select countries, including the United Kingdom, as well as the EU and NATO, to reduce fragmentation and strengthen collective defense. Europe also needs to be more proactive in intelligence sharing, a role that in the past has largely been played by the United States. But just as the EU created Europol to coordinate cross-border law enforcement and counterterrorism operations, Europe could create an “EU service for intelligence cooperation,” as a European Commission report highlighted in October 2024, to fill this gap.

These reforms are compatible with the EU’s existing underlying treaty, which includes its Common Foreign and Security Policy. When constraints arise—for example, if illiberal Hungary objects—the EU could find workarounds such as creating new institutional structures that do not include all EU members, similar to how not all EU states use the euro or participate in the Schengen area, which permits freedom of movement across national borders.

Europeans would do well to remember why they joined into a European Union in the first place. Although reluctant to give up sovereignty to a federal authority, Europe’s small states realized that they would not survive on their own. They were stronger together, and they needed to work with one another to protect themselves as countries. As the historian Alan Milward observed, far from eliminating each country, the European Community was “its buttress, an indispensable part of the nation-state’s post-war reconstruction.” With the United States in retreat, Europe’s nation-states are under threat. By activating what the European project was created to do—build the continent’s power—European countries can secure their future.

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