In May 2013, when I became commander of U.S. European Command and NATO’s supreme allied commander for Europe, I found U.S. and NATO forces well suited for their requirements at the time but ill prepared for the challenges that lay ahead. The United States’ military presence in Europe, which had shrunk significantly since the 1990s, was not oriented toward a specific threat. NATO, for its part, was mostly involved in operations outside the continent, primarily in Afghanistan.

Now that I have completed my tenure, I have the chance to reflect on how U.S. European Command and NATO have evolved since I took up my positions. Over the past three years, the United States and the alliance have shifted their focus to threats closer to the heart of Europe—namely, Russian aggression and the vexing challenges associated with the ongoing instability in the Middle East and North Africa. These threats are of a breadth and complexity that the continent has not seen since the end of World War II. Although the United States and NATO are better prepared to confront them today than they were in early 2014, when Russia illegally annexed Crimea and con­ducted a de facto invasion of eastern Ukraine, there is much more that the United States and its allies must do—above all, improve their abilities to deter the Russian threat and to deal with the problems associated with regional instability on Europe’s borders, namely, inter­national displacement and transnational terrorism. To better prepare for these challenges, the United States should increase the resources available to its forces in Europe and recognize Russia as the enduring, global threat it really represents.

NATO soldiers during a military exercise near Setubal, Portugal, October 2015.
NATO soldiers during a military exercise near Setubal, Portugal, October 2015. 
Rafael Marchante / REUTERS


To appreciate the position the United States and its allies found themselves in when Russia began its intervention in Ukraine, it is helpful to look back to the Cold War. In the final years of that conflict, NATO’s forces and those of the Warsaw Pact enjoyed relative parity. NATO had approximately 2.3 million men under arms in Europe; the nations of the Warsaw Pact had about 2.1 million. Although the Warsaw Pact countries had more tanks, artillery pieces, and fighter jets than NATO, the alliance managed to counter this numerical advantage through its advanced military equipment. NATO’s mission at the time was hardly easy, but it was relatively clear-cut. The West knew how to deal with a potential invasion launched by the Warsaw Pact, and the relative parity between NATO and the communist bloc, along with the doctrine of mutual assured destruction, ensured that such an invasion was unlikely. 

When the Warsaw Pact and the Soviet Union dissolved in 1991, NATO was already developing a strategic vision for Europe’s new security environment that placed less emphasis on nuclear deterrence and the forward deployment of allied forces. The United States and most of its NATO allies dramatically decreased the size of their forces in Europe. Meanwhile, the sudden collapse of Soviet power, which in eastern Europe had held nationalism and instability in check for decades, allowed democratization to begin in newly independent states, but it also led to civil strife, most notably in the Balkans. NATO, then the world’s only capable multinational force, sent peacekeepers there, tipping the balance toward a political resolution of the conflict. Then, in the years after 9/11, the alliance intervened in Afghanistan, and subsequently in Libya, where it also faced challengers without the advanced military capabilities of a near-peer competitor. In other words, in the decades after the Cold War, NATO found a new raison d’être in stability operations and confronting low-end threats. It adjusted its force structure accordingly.

All the while, neither the United States nor NATO was paying enough attention to its old nemesis to the east: Russia, which was working to reassert its influence in many of the areas the Soviet Union had once dominated. In every year after 1998, Russia increased its military spending; at the same time, it was increasingly meddling in the affairs of its neighbors, for example, by suspending gas supplies to Ukraine several times in the years after the Orange Revolution of 2004–5. It was Russia’s invasion of Georgia in 2008, however, that showed just how far Moscow was willing to go to punish states on its periphery for moving closer to the West. The speed with which the invading Russian forces moved into Georgia left no doubt that the operation had been planned far in advance. The United States was focused on the wars in Afghanistan and Iraq and on fighting global terrorism, and Russia saw an opportunity.

Russia’s operation in Georgia formed part of the blueprint for its actions in Ukraine. By seizing Crimea, backing separatist rebels in the Donbas, and sponsoring protests against the pro-Western government in Kiev, Russia showed once again that it was willing to undermine established norms of international behavior to achieve its goals. When the West responded by levying sanctions against Russia that, compounded by low oil prices, resulted in a rapid economic decline, Moscow doubled down, increasing its provocations against NATO ships and planes operating in international territory, intervening in Syria in support of President Bashar al-Assad, and further militarizing the Arctic.

Moscow is determined to reestablish what it considers its rightful sphere of influence, undermine NATO, and reclaim its great-power status. That desire has been evident since 2005, when Russian President Vladimir Putin called the collapse of the Soviet Union “the greatest geopolitical catastrophe of the [twentieth] century”—a preposterous claim in light of that century’s two world wars. It is through this prism that the West must view Russian aggression.


Despite Russia’s growing belligerence, neither the United States’ military nor those of its allies are adequately prepared to rapidly respond to overt military aggression. Nor are they sufficiently ready to counter the kind of hybrid warfare that Moscow has waged in eastern Ukraine. At the height of the Cold War, the United States had more than 400,000 soldiers assigned to Europe; today, there are fewer than 100,000 soldiers assigned to the continent, and 35,000 of them are on rotational deployments. Indeed, even when combined with the forces of NATO, the United States’ military presence on the continent would be hard-pressed to deter a determined Russia. By rapidly invading a NATO ally, Russia could present a fait accompli that would be brutally expensive and difficult for the United States and its allies to reverse.

The imposition of compulsory budget cuts in the United States has compounded these challenges by limiting the Department of Defense’s ability to plan for the future and by mandating risky drawdowns in both the capacity and the capabilities of the U.S. military. Adding to the challenge, the U.S. defense budget has declined in real terms since 2010, even as the country’s international requirements have increased. The United States’ operations in Africa and the Middle East, mean­while, have increased the burden on the country’s assets in Europe, which are frequently used to support U.S. missions in those regions. And an increased focus on the Asia-Pacific as a result of the “rebalance” means that there are fewer resources available for U.S. operations elsewhere.

Other NATO members face similar problems. Only a handful of NATO nations are capable of conducting full-spectrum combat operations, and none can do so for a prolonged period. Although a number of NATO members have halted their slide in defense spending, most are still failing to achieve the alliance-wide target for defense expenditures of two percent of GDP. What is more, although NATO has gained 12 new members since 1990, its total military spending, excluding that of the United States, has decreased: from some $332 billion in 1990 to $303 billion in 2014 in constant 2011 dollars, according to the Stockholm International Peace Research Institute. And the alliance remains responsible for some of the missions it took on after the end of the Cold War: in Kosovo, where it has stationed some 4,800 soldiers, and in Afghanistan, where NATO will likely remain engaged in some form until 2020.

The United States should seek to change Russia’s calculus before Moscow acts aggressively.

The Syrian civil war and persistent instability throughout the Middle East and in North Africa have further complicated matters by encour­aging the largest refugee crisis in Europe since World War II. The resources that NATO members array against these challenges and against the threat of domestic terrorism are simply not available for the alliance’s use elsewhere.

Indeed, as members attempt to cut back on their military spending amid slow economic growth, they must pick and choose where to concentrate their efforts. Countries on the eastern and northern flanks of NATO, such as Poland and the Baltic states, tend to see Russia as the most immediate threat to their security, whereas states closer to the turmoil in the Middle East and North Africa, such as France, Greece, Italy, and Turkey, tend to view the migrant crisis as a more pressing challenge. Facing such challenges, along with the high costs of developing and acquiring the advanced weapons systems that might deter Russia, many NATO countries are instead investing in forces designed for limited territorial defense and internal security. And because adjusting NATO’s broader military posture requires the unanimous agreement of all 28 member states, reforming the force is a slow process.


The good news is that the United States and NATO recognize that the European neighborhood has changed and have begun to act. In June 2014, U.S. President Barack Obama announced the European Reassurance Initiative, an effort to demonstrate the United States’ commitment to the security and territorial integrity of its European allies in the wake of Russia’s intervention in Ukraine. With a budget of $985 million in fiscal year 2015 and an additional $789 million in fiscal year 2016, the initiative has funded new bilateral and multi-lateral military exercises and greater deployments of U.S. forces to the continent, supported by the placement of more U.S. military equipment, including artillery, tanks, and other armored fighting vehicles, in central and eastern Europe. These moves not only are increasing the United States’ combat readiness but also will save the country millions of dollars relative to what it would have cost to repeatedly send similar assets to Europe. The increased funding that Obama has requested for the initiative in fiscal year 2017, of some $3.4 billion, will do even more to improve the United States’ and NATO's ability to deter Russia, in part by allowing the United States to ramp up training programs with its allies, preposition even more military equipment in Europe, build up the military capacities of U.S. partners, and invest in the infrastructure needed to support all these measures. It will also support the development of Army Prepositioned Stocks, which are complete prepositioned sets of supplies and equipment for armored and mechanized brigades; these will allow the United States and its allies to rapidly deploy reinforcements in the event of a crisis. 

Meanwhile, in the summer of 2014, U.S. European Command began Operation Atlantic Resolve, a broad program of action in support of the European Reassurance Initiative. U.S. forces have maintained successive rotational deployments in Poland and the Baltic states for almost two years. In the Mediterranean and the Black Sea region, the U.S. Marine Corps has kept up the nearly continuous rotational presence that it began in 2010, and the U.S. Navy has increased its presence in the Bosporus. The U.S. Air Force, for its part, has significantly ramped up so-called micro-deployments of small teams of fighter and attack aircraft to other NATO countries, where they work with their hosts to exchange tactics and improve interoperability.

NATO, too, is changing. In 2014, the alliance agreed to the Readiness Action Plan to ensure that it can react swiftly to security challenges on its eastern and southern frontiers. The plan includes a number of immediate measures, such as ramped-up military exercises and aerial patrols over the Baltic states, which are aimed at reassuring the popu­lations of NATO countries, deterring Russian aggression, and improving interoperability among national forces. More significant are the long-term reforms that aim to improve the readiness and responsiveness of the alliance’s forces. To begin with, NATO created the Very High Readiness Joint Task Force, a brigade that can respond to crises on extremely short notice. Then, last summer, NATO announced that it would triple the size of that contingent’s parent force, a land, sea, and air group known as the NATO Response Force, to around 40,000 soldiers.

The alliance has also improved its command-and-control structures. In six vulnerable central and eastern European member states, NATO has established small headquarters, known as Force Integration Units, which will help incorporate allied forces into the defense structures of the host countries, ensuring that when NATO troops are deployed to a conflict involving one of its members, they will be able to work seamlessly with forces already in the fight. And in 2015, NATO established two new tactical headquarters in Poland and Romania. Improvements such as these will upgrade the readiness of NATO’s forces, serve as an effective deterrent against would-be foes, and help the alliance better monitor the ongoing instability in the Middle East and North Africa. Taken together, the measures pursued under NATO’s Readiness Action Plan represent the most significant reinforcement of the alliance’s capacity for collective defense since the end of the Cold War.

NATO leaders watch a fly-past by Royal Air Force planes during the NATO summit at the Celtic Manor resort, near Newport, Wales September 2014.
NATO leaders watch a fly-past by Royal Air Force planes during the NATO summit at the Celtic Manor resort, near Newport, Wales, September 2014. 
Andrew Winning / REUTERS


These actions are a strong start, but they are not enough. The foundation of any strategy in Europe must be the recognition that Russia poses an enduring existential threat to the United States, its allies, and the international order. Russia is determined to once again become a global power—an ambition it has demonstrated by, for example, conducting confrontational mock attacks on U.S. forces, as Russian warplanes did to the USS Donald Cook in the Baltic Sea in April, and resuming Cold War–era strategic bomber flights along the U.S. coastline. What is more, as Russia’s intervention in Syria has demonstrated, Moscow will seek out all opportunities to expand its influence abroad. Because the Kremlin views the United States and other NATO members as its primary adversaries, it considers its relationship with the West a zero-sum game. It will continue to do so for the foreseeable future.

The Putin government will not allow any nation over which it has sufficient leverage to develop closer ties with the West—namely, by moving toward membership in the EU or NATO—and it will do every-thing in its power to sow instability in countries such as Georgia, Moldova, and Ukraine. Putin no doubt knows that the EU and NATO will be reluctant to accept a nation as a member if it is caught up in a so-called frozen conflict.

At the same time, Russia will continue to improve its military’s ability to offset the technological advantages currently enjoyed by NATO. Although Russia’s fighter aircraft do not currently match the West’s, the country’s advanced air defenses, coastal cruise missiles, antiship capabilities, and air-launched cruise missiles are increas­ingly capable. If Moscow managed to keep U.S. reinforcements out of a potential conflict between Russia and NATO while preventing Western war­planes from hitting their targets, it would seriously degrade the advantages of the United States and its allies. To this end, Russia is establishing “anti-access/area-denial” zones across its periphery, including in the Baltic and Black Seas, the Arctic, and the Russian Far East. What is more, Russia’s growing footprint in Syria offers Moscow the capability, if it chooses, to threaten U.S. and allied forces operating in the eastern Mediterranean and in the skies over Syria.

Russia has shown that it can cause Washington and its allies significant political and military angst with minimal effort and at relatively little cost. So far, the United States and NATO have consistently reacted to Russia’s provocations rather than preempting them. Instead, the United States and its allies should take a proactive stance that seeks to change Russia’s calculus before Moscow acts aggressively. Under such a strategy, the United States and its allies would determine in advance and then clearly articulate when they will counter Russia’s moves, when they will ignore them, and when they will seek cooperation.

There are certainly opportunities to work with Russia, as Washington and Moscow’s mutual effort to bring Iran to the negotiating table through economic sanctions has shown. In dealing with North Korea, managing drug trafficking in Central Asia, policing the fisheries in the North Pacific, and undertaking search-and-rescue operations in the Arctic, to name only a few, there are further potential opportunities for the two countries to work together on shared interests.

Despite Russia’s growing belligerence, the United States’ military is not adequately prepared to respond.

Even as the United States works with Russia on issues such as these, however, it must not allow its stance against Moscow’s transgressions to soften. The Kremlin respects only strength and sees opportunity in the weakness and inattention of others, so the United States and NATO must stand firm, especially with respect to Russia’s nefarious and coercive attempts to prevent countries on its periphery from choosing to align with the EU and NATO. Washington’s strategy should reassure U.S. allies and ensure that the Kremlin understands the specific consequences that a confrontation would bring.

In order for such a strategy to be effective, the United States and its allies must demonstrate that their forces in Europe represent a credible deterrent. After two decades of shrinking resources, this will require more work. Although U.S. personnel represent the United States’ most important asset, the country must work to balance its military personnel costs with the need to develop and deploy more advanced and capable weapons. The Department of Defense, which cannot afford cost overruns and inefficiencies, should continue to reform its acquisition processes. More broadly, the United States must end the crippling effects of sequestration and prevent the gap between the requirements of the military and the resources available to it from widening further. Other NATO countries must bear some of the burden, too. They must round out the knowledge of counterinsurgency and stability operations that they have developed in Afghanistan with stronger war-fighting and counterterrorism capabilities.

Even as the United States invests in new technologies to offset the strengths of its potential adversaries in the longer term, it must take additional concrete steps. Developing an effective mix of permanently forward-deployed and rotational forces, along with prepositioned equipment and the capacity to rapidly reinforce U.S. forces in Europe with troops from the continental United States, will deter Russia and reassure U.S. allies of Washington’s commitment to do so. General James Amos, the former commandant of the Marine Corps, said it best when he noted, “Forward presence builds trust that cannot be surged when a conflict looms.” As for what form this ramped-up presence should take, the United States should preposition the equipment for two or three additional armored brigades in eastern Europe, along with the supplies to sustain those forces through at least two months of intense conflict. The United States’ nuclear forces remain an essential deterrent, too, so the country should maintain them, enhancing the nuclear exercises that U.S. forces carry out with its NATO allies to demonstrate their resolve and capability to Russia.


Even as the United States and its NATO allies focus on countering Russia, they must not lose sight of the challenges of Islamist terrorism and population displacement, which are rooted in instability and poor governance in the Middle East and North Africa. The United States should be prepared to continue the fight against the Islamic State (also known as ISIS), al Qaeda, and other terrorist groups for some time to come. In this effort, however, U.S. forces should play a supporting role: the main strategy should be to invest in institution building and education, among other measures, to stabilize the poorly governed spaces that give rise to terrorism and displaced populations. The United States, in particular, must consider cooperating with foreign governments whose democratic bona fides are less than perfect. At the end of the day, the United States’ discomfort with some of the governments in the Middle East should not hold back its efforts to meet these challenges.

Of course, just as important as what the United States and its allies should do is what they should not do. To let Russia know that its illegal annexation of Crimea and invasion of the Donbas cannot stand, the United States should not allow the sanctions regime to soften. It should not choose the middle ground in Syria, in Iraq, in Libya, and in other ungoverned spaces. The United States must lead: it should do more to build up the defenses and civil societies of its most vulnerable partners, and it must be willing to make the difficult choice to use force when necessary.

Inaction and indecision on the part of the United States will have consequences far beyond the immediate problems it seeks to address. Unless the country demonstrates its resolve and makes the necessary investments, its adversaries will continue to undermine U.S. interests, and others around the world will lose respect for U.S. power. The cost in blood and treasure to defend the United States and to come to the aid of U.S. allies whose trust has been built up through decades of shared sacrifice will be much greater in the future if the United States fails to act now.

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