C-Archief 2021-2025

A Better Way for Europe to Guarantee Ukraine’s Security How European Forces—and NATO Resources—Can Make the Country Stronger Ivo H. Daalder September 10, 2025 A Ukrainian government building damaged in a Russian strike, Kyiv, September 2025 A Ukrainian government building damaged in a Russian strike, Kyiv, September 2025 Serhii Korovainyi / Reuters IVO H. DAALDER is Senior Fellow at Harvard’s Belfer Center for Science and International Affairs and served as U.S. Ambassador to NATO from 2009 to 2013.

In the weeks since U.S. President Donald Trump’s Alaska summit with Russian President Vladimir Putin, two things have become clear. One is that convincing Russia to end the war is proving much harder than Trump expected. Days after his meeting with Putin, Russia launched one of the largest-ever attacks against Kyiv, employing nearly 600 drones and several dozen missiles; and on September 7, it launched an even bigger drone and missile assault, hitting for the first time a major government building in the capital. A second is that providing Ukraine with the post-cease-fire security guarantee it has long insisted on as part of any resolution to the war is more important than ever. Although Kyiv’s ultimate security rests with maintaining a strong and capable military, Ukraine must also be reassured that European countries and the United States have its back—and Moscow must be convinced that any resumption of war would involve a conflict with NATO countries.

The best and strongest guarantee of Ukraine’s security would be membership in NATO, but Trump has ruled this out. The administration has also stated that Europe, not the United States, should bear the primary burden of any guarantees, declining to promise any specific form of U.S. involvement. This has left European leaders scrambling to produce a formula that could provide what is needed. One essential step was taken in September, when French President Emmanuel Macron announced that 26 Western allies were prepared to support Ukraine “by land, sea, or air” once the fighting stops. But the details of these contributions remain vague, given that so far only Britain, Estonia, France, and Lithuania have publicly pledged to put forces on the ground in Ukraine.

Europe’s quandary is how to turn its determination to reassure Ukraine into a tangible reality. To do so, European leaders will need to ensure that Ukrainian forces are as strong and capable as possible, and draw on the resources of NATO to support those forces, even if outright membership in the alliance is out of the question.

European leaders need to accept the present situation: when it comes to tangible security guarantees for Ukraine, they will be on their own. Any U.S. contribution will be minimal at best. Supporting Ukraine’s military and deploying significant forces in and around Ukraine as part of a NATO operation offers the best way to reassure Kyiv that Europe’s commitments are real. This will not be easy, but doing so is essential to developing a credible path toward ending the war and to ensuring Ukraine’s security. Ultimately, a strong, free, and independent Ukraine is essential for Europe’s own security.

STEEL PORCUPINE To develop effective, long-term security arrangements for Ukraine, European leaders need to focus on three complementary elements. First, they should recognize the importance of Ukraine’s own formidable military and the extraordinary commitment of its people to Ukraine’s sovereignty and independence. These strengths are at the core of Ukraine’s ability to ensure its security and require European support to be sustainable over time. Next, European countries should be prepared to deploy substantial ground, air, and naval forces in and around Ukraine to assist its armed forces in case of a renewed attack. Such a commitment would send an unmistakable signal to Russia that Ukraine’s security represents Europe’s first line of defense. Finally, a true security guarantee will come only when Ukraine is fully integrated into European institutions—including the European Union and, eventually, NATO.

Any agreement with Russia to end the war must preserve all three of these pillars. That means a peace deal cannot impose any limits on Ukraine’s armed forces or its sovereignty and independence. Any deployment of European forces in Ukraine, moreover, is a matter for Kyiv and its European partners, not Moscow, to decide. And Russia cannot have any say over Ukraine’s future security alignments or membership in European and other institutions. Russia, no doubt, will object vehemently to these principles. Denying Ukraine each of these security components has been a core objective of the Kremlin’s war. This is why an end to the fighting is not currently in sight. But if the economic and human costs of war continue to rise, Ukraine and Russia could well decide to stop fighting and agree to a cease-fire or even a more formal armistice. Even in that case, however, each of these three elements of a Ukrainian security guarantee will need to be pursued.

With nearly a million troops and deep warfighting experience, Ukraine provides its own strongest security guarantee. For Europe, then, a key challenge is to harden Ukraine’s defenses to turn it into a “steel porcupine,” as Europe’s top diplomat, Kaja Kallas, has suggested. In other words, Ukraine must be able to mount a powerful response to any future Russian aggression. To that end, Europe must continue to provide Ukraine with the advanced weapons—including advanced air defense systems, combat aircraft, and stand-off missiles—that it needs to defend itself against a larger Russian force. Although the Trump administration has made clear that it will no longer pay for Ukraine’s defense, Trump has welcomed the idea of European nations purchasing U.S. equipment on Ukraine’s behalf. Some of the first major purchases—including Germany and Norway buying additional Patriot air defense systems, and Denmark and the Netherlands buying nearly a thousand air-to-ground missiles—are already making their way to Ukraine.

Sustained European financial support for Ukraine’s own defense industry will as also be important. Ukraine’s defense industry can draw on a long history. For decades, Ukraine played a central part in building the Soviet war machine. And although its defense sector atrophied after Ukrainian independence in 1991, Russia’s full-scale invasion in 2022 jump-started that industrial base again. In 2024, Ukraine produced nearly $10 billion in defense equipment, a total that is expected to rise another 50 percent, to $15 billion, this year. Oleksandr Kamyshin, the former minister of strategic industry who now oversees Ukraine’s defense industry, has suggested that the country has the industrial capacity to produce $35 billion worth of defense equipment every year but is held back by a lack of funds. Providing those financial resources should therefore be a top priority for its European partners.

After three and a half years of war, Ukraine’s defense industry is far nimbler and more efficient than those of its European and U.S. counterparts. Take artillery shells. The United States is still struggling to produce one million shells a year, whereas Ukraine’s factories produced 2.5 million in 2024—a number set to grow further this year. Ukraine’s drone manufacturing has also surged: Ukraine produced two million first-person-view drones in 2024 and expects to hit five million this year. In addition, it has set a goal of manufacturing 30,000 long-range drones, 3,000 long-range cruise missiles, and hundreds of new ballistic missiles in the next year or so. European partners have been critical to these advances. European industry has played a vital role in boosting Ukraine’s defense production through joint ventures that provide technological know-how. Funding from both individual governments and the European Union has also helped expand production. By integrating Ukraine’s growing defense industry into Europe’s ballooning defense industrial base, European allies can help build strong foundations for Ukraine’s long-term security.

BOOTS AND BACKSTOPS In addition to building up Ukraine’s own military resources, European allies need to commit their own forces to establish long-term security for the country. Today, Ukraine’s armed forces are by far the largest and most battle-tested in Europe. Their strength means that deterring Russia from resuming the war—and supporting Ukraine’s defense if it does—will not require a large-scale European military deployment on Ukraine’s frontline. Ukraine can provide most of its own capabilities. Nevertheless, to provide credible security guarantees, Europe will need to make a substantial commitment of its own forces to support Ukraine and be prepared to assist in defeating a Russian attack.

That credibility depends on European deployments. At a minimum, European countries need to deploy four combat brigades—approximately 20,000 troops in total—to Ukraine, including a mixture of mechanized and infantry brigades. These should include mobile air defenses, long-range strike capabilities, and high-mobility forces that would be ready and able to fight Russian forces. In addition, European air forces should dedicate at least ten squadrons of combat airpower—some 200 combat aircraft—to secure Ukraine’s skies and protect ground forces from aerial attack. And a substantial European naval presence should be deployed in the Black Sea to secure Ukraine’s coast and sea lines of communication.

A reassurance force along these lines would constitute a substantial commitment by European countries. Thus far, France and the United Kingdom have taken the lead on pledging troops, with some Baltic nations now joining them. But other European countries, including Poland and Germany, have been more hesitant. Warsaw and Berlin have said that they want to keep forces focused on current defense missions, which in Germany’s case includes the soon-to-be-perman