Planning for a Post-American NATO

Europe may soon find itself in a tight spot. By the end of January 2025, the continent’s most important partner, the United States, could be led by former President Donald Trump, who has said that he would encourage Russia to do “whatever the hell it wanted” to European countries that did not do what he wanted: spend more on defense. The previous Trump administration strained the transatlantic relationship, and the next iteration would almost certainly be worse. Freed from the influence of the traditional Atlanticist Republicans who staffed his cabinet in his first term, a second-term Trump would face fewer obstacles to making good on his threats.

The U.S. election is far from decided, but the magnitude of the change that a Trump victory could bring is far too great for Europe to sit by and hope that the former president loses at the ballot box. Trump has warned that he would immediately cut all U.S. aid to Kyiv and demand a quick end to the war, which would likely require Ukraine to cede a significant part of its territory to Russia. And that could just be the start. Trump has long questioned the value of NATO, so it is not inconceivable that he would strip back the U.S. commitment to defend Europe. He could enact the analyst Sumantra Maitra’s widely circulated “dormant NATO” proposal, in which the U.S. military would provide logistics support as a last resort but leave all other NATO defense responsibilities to Europe, or follow in the footsteps of French President Charles de Gaulle, who removed France from NATO’s military command (but not the alliance itself) in 1966. Assurances that Washington would not disappear from Europe entirely do not make the proposals in Trump’s orbit any less dangerous. NATO is held together by the confidence and resolve of its members; their belief in the alliance would be mortally undermined were Trump to push even an incomplete U.S. withdrawal.

There is no reason Trump could not act quickly. As commander in chief, he could vow never to order U.S. troops to fight for Europe and take steps to withdraw the United States from NATO’s military command. Europe, as a result, would be forced to confront a security crisis on a scale it has not faced since World War II. Without the United States to provide military leadership and capability, European capitals could quickly turn against one another over Ukraine. Countries in central and eastern Europe, for instance, may double down on their commitment to the survival of a strong Ukraine, fearing that a Russian victory would give Moscow the opportunity to rebuild, rearm, and then, with the help of a compliant Belarus and Ukraine, issue new threats across the border. Many western European countries, meanwhile, might decide that, with the United States out of the picture, the best option would be to force Ukraine to make extensive concessions to Russia. A European security alliance could collapse under the weight of such incompatible outlooks.

To avoid the worst-case scenario, European countries and institutions must start planning now. They must be ready for a Trump presidency that could result in a U.S. withdrawal from Europe, which might go so far as to leave the continent unprotected, save for U.S. naval and air forces that could easily be redeployed elsewhere. As they face the dangers of such an eventuality, the continent’s leaders will need to grapple with many hard questions. The most urgent among them fall into three categories: how to structure European security, who should lead the effort, and what capabilities Europe must acquire. From this starting point, Europe can begin to prepare for the potential loss of the continent’s strongest defender by far. 

STRUCTURAL CHANGE

The question of a post-American security structure may be the easiest to answer. If the United States were to truly disengage from Europe, European countries could maintain their security alliances through one of several institutions that Washington would leave behind. Setting aside the potential complication of Canada—which, if it were to remain in NATO even after a U.S. withdrawal, the alliance would be obligated to defend—the most straightforward and best solution would be for Europe to assume control of the North Atlantic Council, the decision-making authority within NATO. The NAC would have to reorient quickly upon a U.S. withdrawal—for obvious reasons, this body itself cannot plan for the United States’ exit while the United States is still a member—but it has the benefits of being familiar to all NATO countries in Europe and having an established secretariat. It also counts Norway and the United Kingdom, significant non-EU security powers, as members. Both have been strong supporters of Ukraine and would be vital players in a future war against Russia. British air and maritime forces in particular protect much of NATO’s northwest flank. Going forward, Europe will need those capacities, as well as London’s nuclear deterrent. Working together through the NAC may be the best possible way to solidify this relationship.

If European countries were to take over the NAC, they could also repurpose NATO facilities, such as the NATO Defense College, that are scattered across the continent. The new NAC could draw on other European institutions for support, too. The EU, for example, could help coordinate the national legislative change and bloc-wide financial planning that will be necessary to prepare European societies for a potential conflict. Finland and Sweden, the most recent entrants to NATO, would have much to contribute to this effort. Decades of neutrality pushed them to develop plans to mobilize in wartime and to build resilient economies and polities, whereas most of their neighbors relied on NATO membership to cover their security concerns. And although the NAC would remain the primary decision-making body for NATO members, the European Political Community, which was established after Russia’s 2022 invasion and counts several non-NATO countries among its members, would play an important role as a forum for discussing security matters that affect the region as a whole.

WHO LEADS EUROPE?

European countries have essentially outsourced geopolitical leadership to the United States for the last 75 years or so. Deciding who could take Washington’s place within a European security structure is thus a challenging proposition. No European country has experience with that job, and there is no natural leader for the rest to converge on.

Germany might seem a likely candidate, given that it has Europe’s largest economy and population. But Berlin, crippled by political indecision, has failed to display leadership so far in the war in Ukraine. Having cozied up to Russia before the 2022 invasion, and joining the United States in limiting aid to Ukraine after, Germany has lost the trust of many of the central and eastern European countries that fear ending up on a new frontline. Olaf Scholz’s government frequently sends mixed messages, with the chancellor’s own Social Democratic Party advocating one policy and its coalition partner, the Greens, promoting another. The openly pro-Russian positions espoused by the far-right Alternative for Germany and far-left Reason and Justice parties, both of which made strong showings in last weekend’s regional elections, raise additional concerns.

France could be a better option. As one of Europe’s two nuclear powers, France would necessarily play an important and immediate role in European security if the United States were to withdraw. The French have a competent military, and President Emmanuel Macron has tried to stake out a leadership position in Europe amid the war in Ukraine by ratcheting up his calls for stronger support for Ukraine and even suggesting that European forces might be deployed there if necessary. Yet Paris, like Berlin, carries serious liabilities. In the early months of the invasion, Macron favored reaching some kind of arrangement with Russian President Vladimir Putin, and today, politicians on France’s increasingly empowered far right and far left, as in Germany, seriously discuss cutting aid to Ukraine. Frontline countries may consider France no more reliable than Germany when it comes to sustaining Europe’s defense.

It is not inconceivable that Trump would strip back the U.S. commitment to defend Europe.

The United Kingdom, Europe’s other nuclear power, would bring many positive attributes to the leadership role. The new British government can stay in place for the next five years, making the country more politically stable than many others in Europe. London, as a consistent supporter of Ukraine, is aligned with Europe’s frontline countries. The United Kingdom also has long-standing defense ties with fellow members of the Joint Expeditionary Force, a military grouping of ten Baltic, Scandinavian, and other northern European nations. If the country had remained in the EU, it could have had the strongest claim to the security leadership of Europe. But after its 2016 decision to leave, it is almost impossible to see EU countries agreeing to British strategic command.

With the continent’s three security heavyweights each hobbled by political weaknesses, Europe could seize the opportunity to make a less conventional choice for its security leadership. Poland has emerged as a strong candidate. It is a large country with a growing economy, and it took defense seriously even before Russia’s full-scale invasion of Ukraine. Over the past few years, Warsaw has undertaken the most substantial military buildup on the continent, increasing both the fraction of its GDP spent on defense and the forces deployed to its borders with Belarus and the Russian enclave Kaliningrad, and its defense budget target of five percent of GDP for 2025 outpaces the rest of Europe. Already seen as a leader in central and eastern Europe, Poland understands frontline countries’ concerns about Russia in a way that a western European government cannot.

Given that Poland shares a border with Belarus, Ukraine, and Russia, its military would be critical in a larger war with Russia. Warsaw, aware of this, is now expending significant resources to upgrade its army and air force. Before the war in Ukraine, a land-centric military such as Poland’s would not have been considered capable of leading European forces. But NATO’s traditional emphasis on air and sea domains was largely a function of the centrality of the United States, which relied on long-range air and sea capabilities to project power across the Atlantic. Without Washington, the picture changes. If Europe is defending itself, its land power, supported by tactical airpower, becomes its bulwark. Thus, once Poland expands its air force—it is now amassing one of Europe’s largest fleets of F-35 and F-16 fighter jets—the country will have a striking case for security leadership.

The key post to fill in a European NATO in the event of a U.S. exit would be supreme allied commander Europe, the role that oversees all NATO military operations and that has always been held by an American. If the need arises, a Polish officer could be selected as the first supreme allied commander for a European NATO. This choice would make political and strategic sense to show both frontline states and Russia that Europe is serious about protecting its eastern flank. A strong signal of this kind is sorely needed; the appointed successor to Jens Stoltenberg as NATO secretary-general, Mark Rutte, most recently served as prime minister of the Netherlands, a country that has consistently failed to meet the NATO defense spending target of two percent of GDP. Elevating a Polish commander would also smooth the way for a civilian leader from western Europe, ensuring the political balance that would be crucial to European unity in the early stages of post-American security planning.

BUILDING CAPACITY

In addition to leadership, Europe has outsourced many essential defense capabilities to the United States. European governments have often thrown their limited funds into building a small number of flashy and exorbitantly expensive pieces of equipment, such as the British Ajax land vehicle. Europe’s country-by-country weapons production is also wildly inefficient. Across the ten main categories of major weapons systems—such as fighter aircraft or destroyers—the United States maintains 33 types of systems. Europe maintains 174. This has limited European militaries’ interoperability and created a logistic nightmare. Meanwhile, the continent has neglected to develop the basic capabilities it would need if the United States were to draw down.

Perhaps the most glaring among them is a system for intelligence sharing among European states. For decades, Europe has relied on the Five Eyes—the intelligence network that includes Australia, Canada, New Zealand, the United Kingdom, and the United States—to conduct much of its intelligence work. All members of this group make valuable contributions, but the United States does the bulk of the data collection. Washington’s retreat from Europe would thus disrupt the flow of information.

If Europe were to lose access to the United States’ high-end, space-based intelligence, surveillance, and reconnaissance systems before it can build up an intelligence structure of its own, European countries would have to rely on local sources for data collection and analysis. Although making the transition would be difficult, it may have upsides for Europe. Despite its vast intelligence-collection ability, the United States has done a poor job of understanding Russian power, evident in its gross overestimation of Russian military capabilities before February 24, 2022. Reams of data, it turns out, do not always produce good intelligence or insight. Some of the best intelligence work on Russia over the past few years has in fact come from smaller countries with more specialized knowledge. The Baltic states and the Nordic states, for instance, have consistently provided useful information about Russian capabilities and intentions. Ukraine, too, has done a credible job analyzing Russian strengths and weaknesses, and Kyiv’s intelligence capacity has enabled operations such as a strategic air campaign against Russian oil production. Despite the individual capabilities of European states, however, quickly agreeing on and setting up the architecture to share intelligence among European NATO members will be a challenge in the absence of U.S. leadership.

Decades of peace and Europe’s concentration on boutique capabilities have also left the continent with insufficient weapons arsenals. The war in Ukraine has demonstrated that success in battle depends on each side’s ability to sustain munitions production and supply from factory to foxhole. Whether it is guns, planes, or ships, equipment does not last long once war starts. Both Russia and Ukraine have already lost the combined number of tanks in storage in France, Germany, Poland, and the United Kingdom many times over. Ammunition runs out quickly, too; artillery fire at the volume seen in Ukraine would have depleted Europe’s pre–February 2022 stockpiles in short order. Kyiv and Moscow have also been drawn into an intense battle to manufacture drones, which have become indispensable in this war and which neither side began the conflict with significant capacity to produce.

Europe must recognize that stocking its peacetime equipment locker will be essential to give its combined militaries time to mobilize when a conflict erupts. At the moment, a European NATO is not a going concern as a warfighting economy. European countries have not moved as quickly as the United States to address their production capacity shortfalls—a problem they will need to rectify in order to plan for an end to or a drastic reduction in U.S. material support for Ukraine.

Beyond ramping up production, a European security body will have to assume responsibility for its own research and development—a task that has largely been farmed out to the United States. Here, at least, Europe has a head start. NATO’s London-based Defense Innovation Accelerator for the North Atlantic, which became operational last year, has begun to extract lessons from the war in Ukraine, especially regarding dual-use technologies that originate in the civilian sphere. If they were to lose the United States, European countries could repurpose and expand this model to fill the resulting gap. To preempt individual countries’ protectionist impulses to bring investments home—which would replicate the inefficiencies of Europe’s small-scale, national weapons production—the European Political Community should negotiate a framework for joint research and development.

Logistically, Europe would have to confront issues related to deployability. Without U.S. capabilities, European militaries could not maintain any kind of global presence; they do not have the capacity for long-distance air deployments of fighting units on their own. This problem is not yet urgent. The war in Ukraine is localized, and European countries can ship most weaponry by road or by rail. But Europe will need to use this breathing space to invest in areas where it now falls short, such as land power and the full breadth of tactical airpower, while it integrates the capacities of European militaries.

As long as Russia maintains its vast nuclear arsenal, Europe will need to protect itself.

Finally, a European NATO might have to confront life without the U.S. nuclear deterrent. This problem could be the single biggest one it faces. Some of the proposals on the table in pro-Trump policy circles suggest that the United States would maintain its nuclear umbrella over Europe even as its conventional forces withdrew, but the logic of such a plan is questionable at best. A United States with little military presence on the continent—and with an administration that looks rather benignly at Putin—could not credibly warn Europe’s enemies that it would put its nuclear weapons in play in the event of an attack. This is not to say Europe should reject a slimmed-down U.S. deterrent if a Trump administration were to offer one. But it would also need to build up a credible European nuclear deterrent, separate from the United States.

In the short term, the job would fall to France and the United Kingdom, which both have small nuclear arsenals. Together they must be able to present Russia with a sufficiently compelling nuclear threat that Moscow will not risk using nuclear weapons on Ukraine or other states in central or eastern Europe. The immediate challenge will be coordinating the deployment and refitting of the British and French nuclear arsenals to ensure that, at any given time, they maintain enough workable forces to be a credible deterrent. Furthermore, London and Paris must begin to expand their deterrents to the rest of the continent. They could, for example, allow other European countries—especially those on the frontline—some influence over British and French nuclear command, which would help assure those countries that they are well and truly covered. 

In the long term, the nuclear deterrent would have to be fully Europeanized. In addition to involving the entire continent in the command structure, Europe would have to manufacture a nuclear delivery system. At present, European states have the ability to produce nuclear warheads on their own. But they have outsourced the means to deliver those warheads—the United Kingdom today shares a nuclear missile fleet with the United States. If Washington were to withdraw, Europe’s nuclear capacity would need to be fully independent. As long as Russia maintains its vast nuclear arsenal, Europe will need to protect itself from Russian nuclear blackmail.

TIME TO ACT

Time is a precious commodity in war. And today, with a war on its doorstep and the United States threatening to push European security to its most precarious point in decades, the continent is wasting it. European countries should have started planning for the possibility of a Trump return at least a year ago, when the high chance of such an outcome became apparent, giving themselves more time to make preparations. Instead, European governments stuck their heads in the sand. If Trump is elected, such denial will have to end. European NATO states will be forced into action to secure the continent and protect the freedom of its people. It is far better they approach that weighty task as rationally and with as much foresight as possible than in a haphazard rush.