Barry Posen | Foreign Affairs
April 21, 2025

"Contrary to what is widely believed, Europeans have most of the military wherewithal needed to create such a force. The question is whether they have the will."
—SSP's Barry Posen in Foreign Affairs
Ever since U.S. President Donald Trump began his effort to settle the war in Ukraine, European leaders have tried to assemble a military coalition capable of defending Kyiv. They have promised, specifically, to station forces in Ukraine. “There will be a reassurance force operating in Ukraine representing several countries,” said French President Emmanuel Macron in March. British Prime Minister Keir Starmer called for a “coalition of the willing” to help protect Kyiv.
This initiative may seem novel and bold, but it is old-think disguised as new-think. Europeans can call these forces whatever they want—peacekeepers, peace enforcers, a reassurance force, a deterrent force. But European leaders are simply repackaging NATO’s 1990s Balkan peacekeeping model for Ukraine. Penny packets of military force would be spread around the country to send the Russians a deterring message. Yet these forces would have limited combat power, and their credibility would depend on the promise of U.S. military force in reserve. European leaders even admit that their forces must be “backstopped” by Washington, which could provide massive air support in the event that the continent’s ground troops are attacked.
The scheme depends on Trump’s support and Russian President Vladimir Putin’s acquiescence. And both of them have already rejected their appointed roles. Trump is no more likely to commit the United States to wage war in Ukraine under any circumstances than was the Biden administration, which refused to do so. Moreover, the European plan would also have the effect, almost surely intended, of anchoring a wayward United States back into NATO, a project that U.S. Vice President JD Vance has repeatedly and categorically rejected. To Putin, meanwhile, acceptance of the European scheme would mean abandoning a key war goal—keeping Ukraine out of NATO and NATO out of Ukraine. European leaders get high marks for diplomatic subtlety as they attempt to disguise this two-pronged effort to rescue victory from the jaws of defeat. But it is very unlikely that either Putin or Trump will bite.
Even if Trump and Putin were to accept such a scheme, Europeans should not want to pursue it. The continent’s people face many potential threats from Russia, so it is foolish for them to tie down their readiest forces in garrisons across Ukraine. They may deter Russia there, but the forces would be unavailable for anything else. This kind of mission would lure European armies into rotating units through these positions in a way that doesn’t leave their soldiers far from home for long periods. Every unit will either be getting ready to go to Ukraine, be somewhere in Ukraine, or will just have returned from Ukraine. This routine is not a formula for a combat-capable army.
So what should Europe do, not only to deter future Russian threats to Ukraine but also to improve its ability to deter Russian aggression in the continent’s east and southeast? The answer is simple—Europe must organize what military planners call a “mass of maneuver” that can quickly deploy where it is needed. Europe cannot know in advance whether a refreshed Russia would renew attacks on Ukraine, move forward into Belarus, threaten Poland, or snarl at the Baltics. As a result, its officials must consolidate meaningful combat power that can intervene quickly wherever and whenever needed. That means they must stop distributing European military forces over the continent’s east and southeast simply as symbols of their commitment, linked to a U.S. cavalry that may no longer ride to the rescue. Rather, they must conceive of European military formations as scarce, expensive, and potentially lethal combat power, which can be deployed as a concentrated fist with the ability to fight independently, under either a NATO or an EU banner.
Contrary to what is widely believed, Europeans have most of the military wherewithal needed to create such a force. The question is whether they have the will.
ARMED, NOT READY
In their Trump-induced panic, European military leaders and pundits have spent the last few months talking about all the combat power that Europe does not have. But they have failed to evaluate and consolidate the combat power that Europe does have. For example, General Mikhail Kostarakos, the chair of the European Union Military Committee, observed that Europe lacks the “strategic enablers that would render it capable of independently performing the full range of tasks associated with the missions and operations it launches”—such as airlift and aerial refueling; intelligence, surveillance and reconnaissance; satellites; and air and missile defense. But Europe does have many of these systems, just not as many as commanders would prefer. Europeans may not have spent what the United States or NATO itself asked of them over the last decade, but they have spent hundreds of billions of euros. They have hundreds of thousands of people under arms and possess meaningful numbers of ground, air, and naval units.
Europeans, in other words, have combat power. To deter and defend themselves, what they need to do is consolidate that combat power and either deploy it close to the possible areas of a Russian challenge or at least demonstrate that they can do so in short order. In the first instance, this means being able to reinforce Poland, which by reason of size, location, and topography is both the eastern linchpin of European defense and the ideal base from which to counter Russian threats against the Baltic states and the continent’s southeast. It is also the ideal place from which it can intervene in Ukraine, should Europeans choose to do so.
To achieve this aim, the continent should fulfill the NATO Readiness Initiative, a proposal spearheaded by Jim Mattis, who served as U.S. secretary of defense from 2017 to 2019. This initiative called for NATO to develop the ability to deploy 30 battalions, 30 squadrons, and 30 ships to eastern Europe in 30 days. These four 30s were never achieved, even when the United States almost surely would have been a key contributor. It might thus be hard to see how Europe will succeed now. But much of the problem then was that Europeans were simply not scared enough to do their part. They are scared now, and that energy can be harnessed to fulfill the initiative and do even more.
[Continue reading full article here]
From Foreign Affairs