Foreign Affairs - The Coming Crisis of NATO Deterrence Nuclear Guarantees Cannot Replace U.S. Forces in Europe - Celeste A. Wallander - May 28, 2026

 Foreign Affairs 

The Coming Crisis of NATO Deterrence

Nuclear Guarantees Cannot Replace U.S. Forces in Europe

Celeste A. Wallander

May 28, 2026

A NATO exercise in Bemowo Piskie, Poland, May 2026

Kuba Stezycki / Reuters

CELESTE A. WALLANDER is Executive Director of Penn Washington and an Adjunct Senior Fellow at the Center for a New American Security. She was Assistant Secretary of Defense for International Security Affairs and oversaw U.S. military assistance to Ukraine during the Biden administration.

President Donald Trump is making a dangerous bet in Europe. This month, the United States announced that it was canceling the deployment of a long-range precision strike battalion to Germany and withdrawing some 5,000 troops from the country. It also abruptly canceled a rotational 4,000-to-5,000-strong combat team bound for Poland, following the earlier cancellation of a similar deployment to Romania in 2025. (The White House has suggested that new forces may still go to Poland but has not specified whether those would come from the United States or be redirected from Germany.) This week, European allies have told media that the Pentagon has informed NATO that it will shrink the forces Washington would rapidly deploy to Europe in a crisis—that is, in the event of a Russian attack on alliance territory.

At the same time, the Trump administration has sought to reassure allies that its commitment to Europe’s defense remains undiminished, pledging to sustain the nuclear umbrella over NATO. This seemingly tidy solution to burden sharing—fewer boots on the ground, an ultimate backstop—may appeal to some American voters, but it is strategically dangerous, eroding the foundations of the deterrence that has protected the transatlantic alliance for decades.

Rather than reinforcing stability in Europe, the Trump administration’s approach invites Russia to test NATO’s escalation dominance—that is, the ability to impose unacceptable costs or failure on the adversary at every step on the escalation ladder, forcing it to back down rather than escalate. Drawing down U.S. forces reduces that dominance and weakens deterrence against Russian aggression in Europe. Over time, a cycle of escalation could leave an American president with an unenviable choice: back down or risk nuclear conflict.

The key to deterring Moscow lies not at the top of the escalation ladder, where nuclear weapons are in play, but on its lower rungs, where conventional weapons are what matters. The goal should be to deter Russian President Vladimir Putin from ordering any move against NATO. By the time Russia has seized limited territory on the alliance’s eastern flank and dared Washington to risk nuclear war to reverse its gains, the United States will be left with only the worst options.

To prevent such a scenario, Washington must maintain the forces in Europe that only the United States can provide and that Moscow fears most: long-range precision strike capabilities from air, land, and sea. And it must signal to Moscow that the United States would not stand aside in the initial phase of a Russian attack, waiting to see whether Europe’s conventional forces can repel the attack on their own. The Trump administration is right to press European allies to spend more on defense, but it cannot stop there. Doing so would hand Russia the escalation dominance it has long sought and bring the United States to the brink of nuclear war.

WHAT MOSCOW FEARS MOST

Over the past two decades, the Kremlin has come to fear the ability of the United States to sustain conventional military operations over not just months but years. Putin watched the United States strike Serbia in 1999 to pressure its leadership into halting military operations against Kosovo. He saw U.S. forces overthrow the Taliban and hunt down al-Qaeda operatives in Afghanistan. And he looked on as the United States invaded Iraq, destroyed one of the largest militaries in the Middle East, toppled the regime, and then sustained operations there for over a decade. Americans recall these campaigns and see failures and forever wars. But those same campaigns look different from Moscow. The Russian leadership may smile at the costs the United States has borne, but it fears the astonishing dominance that the United States has achieved in conflicts across the globe.

The challenge Moscow faces in any confrontation with NATO does not center merely on the alliance’s conventional forces along its eastern flank. The true obstacle to any designs the Kremlin might harbor is the United States’ global reach—its ability to strike deep within Russian territory against logistics, transport, operations, and leadership to thwart any move against NATO. This is what Moscow saw in Serbia, Afghanistan, and Iraq.

Moscow’s predicament is compounded by the United States’ demonstrated ability to sustain advanced multidomain military operations via air, land, and sea—all supported by extensive global communications and intelligence, over months and years, while supplying its allies and partners for a long fight, as well. After Russia’s seizure of Crimea in 2014, Western analysts debated whether the Kremlin might attempt a repeat in the Baltics: manufacture protests among ethnic Russians in one or more of those NATO member countries and then move rapidly to defend them by seizing territory. But the Russian military knew then that U.S. global military reach and logistics would likely doom any such gambit.

Today, Russia remains deterred in the face of U.S. escalation dominance. As long as the United States maintains a formidable presence in Europe, Moscow will not attempt against a NATO country what it tried against Ukraine in 2022: ground, air, and sea attacks to seize airports, roads, ports, and command centers. But if Washington retrenches from the continent, Moscow’s calculations will shift.

Russia’s most advanced forces—its airpower, multi-platform naval strike missiles, and ground-based cruise, ballistic, and hypersonic missiles—have not been fully deployed against Ukraine but remain reserved for a potential confrontation with NATO. Those forces will sit idle as long as the United States maintains its dominance in long-range precision strike capabilities and its ability to ship reinforcements and materiel across the Atlantic and forward to the fight. From 2022 to 2025, U.S. weapons helped Ukraine defend itself against Russia’s invasion—and the United States was only a supplier, not a combatant. In defense of the alliance and the American homeland, the United States would be far more formidable; Russia would face more soldiers, more equipment, and overwhelming resupply.

INVITING AGGRESSION

The United States cannot leave the conventional rungs of the escalation ladder to Europeans, standing aside and merely promising to exercise nuclear options if all else fails. Even as European countries field significant conventional forces, procuring F-35 fighter jets and long-range precision strike artillery, they lack the global reach and logistical staying power that the United States brings to NATO. Any temptation on the part of Moscow to strike the alliance and seize an advantage over its eastern members has, until now, been checked by the depth, scope, and persistence of U.S. forces.

To grasp how seriously the Kremlin takes the problem of U.S. escalation dominance, it is important to understand how Russian military doctrine has evolved. In 2020, Moscow announced that it would permit the limited use of nuclear weapons when an enemy’s conventional attack “threatens the very existence of the state.” Many analysts dismissed this as an unlikely scenario in a conventional war with NATO and therefore failed to take it as seriously as they should have. In fact, the change in policy reflected Moscow’s assessment that the United States would use precision long-range conventional strikes early in a conflict to eliminate the Russian leadership and destroy the strategic assets needed for a second strike. Moscow’s threat of limited nuclear use—climbing the escalation ladder—was a public bid to establish escalation dominance. The Kremlin understood that Washington could mount a sustained conventional campaign, using unmatched advanced strike capabilities on a vast scale, against Russian command, control, and deep military assets. No lightning strike-and-grab operation on NATO’s eastern flank could succeed against that.

But Moscow’s confidence is rising. Canceling the combat teams to Poland and Romania eliminates the persistent rotational presence and joint allied training in the territories that Moscow would attempt to seize and hold, not only reducing the geographical depth of U.S. military presence but very clearly signaling a hands-off approach to forward defense that creates a break in the escalation dominance ladder. And when the Trump administration canceled the long-range precision strike battalion to Germany, it granted Russia strategic depth for supply, reinforcement, and command operations behind the frontlines.

By pulling the unit and signaling that the United States will commit less to reinforce the alliance in a crisis, the Trump administration has effectively delegated conventional defense to Europe, weakening the elements of deterrence Moscow fears most. Now, Russia could be tempted to seize territory in the Baltics or Poland through its client state Belarus and dare NATO to escalate, knowing that its doctrine permits limited nuclear strikes against even conventional forces that threaten newly held territory. The result is a higher risk of nuclear confrontation.

Should Moscow seek to exploit the drawdown of U.S. forces in Europe and encroach on NATO territory, Washington may have to decide whether to threaten nuclear use to compel Russia to retreat. Given Russia’s extensive nuclear arsenal and long-standing doctrine to answer U.S. nuclear use with strikes against the U.S. homeland, a collapse of conventional deterrence in Europe is not certain to end there.

CREDIBILITY ALL THE WAY DOWN

Early in the Cold War, once the Soviet Union had deployed strategic bombers and intercontinental ballistic missiles, U.S. policymakers wrestled with a difficult question: to deter an attack on Europe, should Washington threaten Russia with nuclear war and risk a strike on the American homeland? The answer was to strengthen credibility all along the escalation ladder. Washington invested in strong multidomain conventional capabilities and deployed nuclear-armed fighter aircraft to NATO air bases in Europe. The integration of U.S. conventional and nuclear commitments to the alliance was central to escalation dominance, credible deterrence, and ultimately the Cold War’s peaceful end.

The conventional and nuclear capabilities of both the United States and Russia have changed dramatically since the Cold War, but the fundamental logic of credible deterrence and escalation dominance in Europe remains. To convince Moscow that an attack on NATO cannot succeed, Washington must continue to provide what Russia fears most: long-range precision strike capabilities, rapid reinforcement by advanced conventional forces, and the air and naval logistics needed to fight over months or years.

The United States’ European allies have awakened to the need to spend more on defense. They are putting more advanced weapons systems into production, and at the 2025 NATO summit they agreed to spend a minimum of five percent of GDP on defense. But unless the United States remains central to thwarting Russia’s war plans from the opening hours of any attack, Moscow will see the weaknesses in NATO’s escalation ladder and may be tempted to exploit them, asserting its own escalation dominance and daring Washington to test it.

Moscow will be deterred only by an integrated strategy that promises Russian failure. If Washington signals an unwillingness to engage in conventional military action to defend Europe, Putin will conclude that Russia has escalation dominance on the continent and may climb the conventional rungs. That would leave the American president with a stark choice: concede Russian gains or leap to the nuclear rung. The United States would then face a historic strategic dilemma of its own making.