from Center for Preventive Action and Europe Program

Preventing a Wider European Conflict

Contingency Planning Memorandum No. 38

Russian servicemen drive tanks during military exercises in the Leningrad Region, Russia, released on February 14, 2022. Russian Defense Ministry/Reuters

To prevent Russia's ongoing invasion of Ukraine from escalating into a wider European conflict, Thomas Graham recommends that the United States bolster its deterrence efforts with NATO partners, while leaving the door open for Russia to de-escalate. 

March 8, 2022

Russian servicemen drive tanks during military exercises in the Leningrad Region, Russia, released on February 14, 2022. Russian Defense Ministry/Reuters
Contingency Planning Memorandum
Contingency Planning Memoranda identify plausible scenarios that could have serious consequences for U.S. interests and propose measures to both prevent and mitigate them.


The large-scale Russian invasion of Ukraine now underway could quite plausibly precipitate a wider conflict in Europe. The United States is focused primarily on raising the costs to Russia with punishing sanctions and reassuring North Atlantic Treaty Organization (NATO) allies neighboring Russia of its commitment to collective defense. Less attention has been given to containing the war to Ukraine and preventing its escalation into a broader European conflict.

Thomas Graham
Thomas Graham

Distinguished Fellow

The stakes are enormous. The ripple effects of a wider conflict in Europe would spread across the globe, stressing the geopolitical, economic, and institutional foundations of the international order the United States has fashioned and underwritten since the end of the Second World War. It would test the resilience of the U.S. global system of alliances, the international financial system, global energy markets, arms control regimes, and global institutions in the face of ever more violent great power competition. No region of the world would be spared, although developments on the Eurasian supercontinent, the other locus of world power and economic might outside North America, would bear the gravest consequences for U.S. interests.

The Contingency

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Vladimir Putin

NATO (North Atlantic Treaty Organization)

The Russian military intervention in Ukraine could easily escalate into a larger conflict stretching from the Baltic to the Black Sea and further west into Europe. Although Russia, wielding massive military superiority, might overrun Ukrainian forces in a matter of weeks, stabilizing and pacifying the country will likely prove to be a grueling and costly affair. A significant Ukrainian resistance movement is almost certain to emerge. With sustained Western support, it could prolong the warfare for months, if not years. The first wave of sanctions that Washington has levied on Moscow could be followed by others in a continuing effort to raise the cost to Moscow and force it to yield. A negotiated end to the conflict will not come easily, since Washington has framed it in Manichean terms as a world historical struggle between the democratic West and the aggressive, malevolent, and autocratic Russia. Anything short of “victory” will be decried as surrender or appeasement in the West, while Russia will not capitulate on a matter it considers vital to its security and prosperity.

The stage is thus set for an escalating cycle of violence, with Moscow seeking to stamp out a Ukrainian insurgency and retaliate against Western efforts to stop Russia’s advance. If the conflict wears on, Moscow could be increasingly tempted to expand its military operations further into Europe to achieve its goals.

As a first option, Russia could intensify pressure on states neighboring Ukraine (e.g., Hungary, Poland, Romania, and Slovakia) that could provide safe havens for insurgents or the inevitable government-in-exile. It will doubtless reinforce its military presence in Kaliningrad and elsewhere in the Baltics and patrol the Baltic Sea more aggressively. It could deploy hybrid-war tactics—cyberattacks, disinformation campaigns, and economic sabotage—to destabilize countries providing safe havens. If those actions did not sufficiently degrade the resistance, Moscow could even launch direct attacks on insurgents and their supporters outside Ukraine, as well as attempt to assassinate leading figures in the government-in-exile, akin to the attacks it has made on Chechen rebels and Federal Security Service (FSB) defectors in Europe in recent years. Such steps could, at a minimum, draw frontline NATO states directly into the military conflict with Russia, obligating the United States and other allies to come to their defense.

To build up further pressure, Moscow could also “weaponize” the inevitable refugee flows into neighboring states. Refugees, who would likely number in the millions, would move first into unoccupied Ukrainian territory but eventually into adjacent European states, which have shown little tolerance for outsiders. Moscow could use harsh military and police tactics that would increase the number of refugees and seek to guide them into countries where they would create the greatest socioeconomic stress, such as Moldova. In addition, Moscow could increase the tension by pushing Belarusian President Aleksandr Lukashenko to again seek to push thousands of Middle Eastern migrants across the borders into Poland and Lithuania. That could lead to border clashes, as it almost did on occasion last fall, with Russia supporting its ally, Belarus, and NATO states coming to the defense of allies under attack.

A second option Moscow could pursue is opening up a second front in the Balkans. In recent years, Russia has taken a number of destabilizing actions in the region, seeking to weaken Montenegro after its accession to NATO, exacerbate tensions between Serbs and Bosniaks in Bosnia-Herzegovina, and undermine relations between Serbia and Kosovo. As it fought in Ukraine, Russia could encourage Republika Srpska leader Milorad Dodik to press for separation from Bosnia, threatening to reignite the bitter wars of the 1990s in the former Yugoslavia. A Balkans war would complicate the security calculus of all countries in the region, as well as that of Germany and France, which have significant interests there. To quell the fighting, NATO countries could decide to use military force against Bosnian Serb forces enjoying Russian support.

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Vladimir Putin

NATO (North Atlantic Treaty Organization)

If the conflict wears on, Moscow could be increasingly tempted to expand its military operations further into Europe to achieve its goals.

A third, riskier, option would be to directly attack the United States, the country that Moscow believes is orchestrating a larger anti-Russia campaign. In response to Western sanctions designed to crater Russia’s financial system and undermine critical industries, Moscow could launch major cyberattacks against U.S. critical infrastructure. If a cyberattack were to take down a major financial institution or corrupt its records, the ensuing havoc in U.S. markets could prompt overwhelming public and congressional pressure for a forceful response.

The U.S. and NATO response to Russian actions will impact Moscow’s decisions on the conduct of the conflict. Both a weak response and an excessively harsh one could lead to escalation. In the first case, Moscow could be tempted to press militarily even further into Europe to enlarge its sphere of influence. Vladimir Putin has demanded that NATO withdraw its forces back to the lines they held in 1997, when the NATO-Russia Founding Act was signed and the first wave of post−Cold War expansion remained in the future. His remarks announcing the start of hostilities against Ukraine hinted at a broader effort to restore Russia’s control over all of the former Soviet Union. That could include military action against the Baltic states, especially Lithuania, through which Moscow could try to carve out a land corridor to Kaliningrad, a Russian exclave on the Baltic Sea. NATO would have little choice but to provide military aid to those states if it did not want to forfeit its role as the central pillar of European security.

Crippling sanctions, meanwhile, could provoke Putin to lash out with greater violence. If Putin felt cornered, he could escalate the conflict either horizontally to other countries or vertically to the nuclear level in a desperate effort to save himself, his regime, and, in his mind, Russia itself. And he could find considerable public support for such a reaction. Already, some Russians believe that U.S. and EU sanctions are aimed not simply at the leaders behind the war but, by cratering the economy, at all Russians.

Warning Indicators

As is the case with the current crisis in Ukraine, Moscow’s intentions will remain ambiguous. The indicators of an approaching escalation in the conflict beyond Ukraine are likely to fall into three categories.

The first indicators that political and military conditions are increasing the risk of broader conflict include a breakdown in channels of communication with Moscow. The absence of active diplomatic ties would preclude a negotiated resolution of the conflict in Ukraine. An end to U.S.-Russian military-to-military channels would undermine any effort to avoid direct military conflict between the two countries. Another indicator would be major insurgent successes that dramatically increase Russian casualties. Moscow would be tempted to move more aggressively against insurgent safe havens rather than capitulate on what it considers to be its vital interest in Ukraine.

A wider European conflict would pose the stiffest challenge to the global standing of the United States since the end of the Cold War and to the international system it has built and underwritten for decades longer.

Second are the indicators that Moscow is preparing for a broader conflict, which it would undoubtedly argue had been forced by Western actions. Such signs include Kremlin efforts to prepare the Russian public for a wider conflict, which could entail official statements, greater media focus on escalating Western “aggression,” an increased pace of civil defense drills, and mobilization of reserves. Another indicator includes the massing of Russian forces in the Baltic region. It could include such moves as aggressive hybrid actions to destabilize Poland and the Baltic states, coupled with efforts to rally indigenous ethnic Russian communities against their governments.

Third are the indicators that Moscow is intentionally seeking to widen the conflict. This could include greater support for Bosnian Serb leader Dodik, such as diplomatic and financial backing, and provision of weapons. They could also encourage Serb leaders to more assertively pursue their grievances against Kosovo.

Implications for the United States

A wider European conflict would pose the stiffest challenge to the global standing of the United States since the end of the Cold War and to the international system it has built and underwritten for decades longer. It would test the durability of its global system of alliances and the efficacy of international regimes and institutions that have guarded world peace, security, and prosperity. The challenge would come at a time when the United States itself is in immense disarray, as a deeply polarized polity confronts massive domestic problems—the pandemic, inflation, racial justice, and cultural wars—that leave less time and fewer resources for foreign matters. The United States will be tested to see whether it can muster the will, energy, and creativity to execute an effective policy toward the unfolding crisis in Europe.

At home, public attention has been focused on developments in and around Ukraine, but the Joe Biden administration cannot ignore the home front. In response to U.S.-levied sanctions, Russia can be expected to step up its cyber operations against the United States. It will more actively sow disinformation, seek to exacerbate domestic tensions, and paralyze critical infrastructure. The severity of the attacks will likely rise in proportion to the harshness of the sanctions Washington levies on Moscow.

Abroad, the fate of the transatlantic community, a central pillar of U.S. security and prosperity, would be a stake. One of the Biden administration’s priorities, as laid out in the Interim National Security Strategy Guidance released in March 2021, is repairing U.S. alliances—especially with Europe—after four disruptive years under President Donald Trump. Although relations are more cordial, significant substantive differences remain and the willingness of allies to align behind a common purpose for the long haul remains questionable.

The United States’ allies have rallied behind a harsh set of sanctions in response to Russia’s invasion of Ukraine, but preserving unity as the conflict drags on remains a challenge, especially if sacrifice is spread unevenly across NATO, as will most likely be the case. Putin will seek to exploit divisions through differentiated levels of pressure on NATO members, targeted energy cutoffs, offers of negotiation, and the like to advance two long-standing Russian goals: the end of NATO as a collective defense organization and the erosion of the foundations of the EU. Should he succeed, the new order that would emerge in Europe is far from certain. But Russia would undoubtedly play a central role in its formulation, and almost any conceivable new order would diminish the power and role of the United States on the continent.

A similar situation obtains in the Indo-Pacific region. The Biden administration spent 2021 bolstering relations with its allies and partners—energizing the Quad (the United States, Australia, India, and Japan), and cutting a submarine deal with the United Kingdom and Australia—to meet the growing strategic challenge posed by China. A major, prolonged European distraction could undo further efforts to pivot to Asia, raise doubts among allies and partners about the credibility of the U.S. commitment, and free China to pursue its objectives with greater vigor. The United States could avoid this outcome by pursuing lesser goals in Europe—leading to the quicker development of a new order less favorable to American interests—or by a massive buildup of its military capabilities that would enable it to play a major, perhaps decisive, role in both regions. The latter would have to come at the cost of the Biden administration’s domestic priorities. Whether the Biden administration could muster sufficient domestic political support, if it decided to move in this direction, is far from certain.

The United States’ allies have rallied behind a harsh set of sanctions in response to Russia’s invasion of Ukraine, but preserving unity as the conflict drags on remains a challenge, especially if sacrifice is spread unevenly across NATO.

In addition to regional challenges, a major European conflict would also stress critical international regimes and institutions. One of the first victims would likely be the arms control regime that has served as the foundation of strategic nuclear stability for the past fifty-plus years. The United States withdrew from some central elements—including the Anti-Ballistic Missiles (ABM) and the Intermediate-Range Nuclear Forces (INF) treaties—but two critical elements have remained in place: the New START treaty and the Nonproliferation Treaty (NPT). A wider conflict in Europe would all but guarantee that the United States and Russia could not agree to a follow-on treaty to the New START treaty before it expires in 2026, and the NPT review conference tentatively scheduled for August 2022 would fall by the wayside. As a consequence, the incipient arms race now underway, fueled by new technologies—hypersonics, cyber tools, and artificial intelligence—would accelerate. A new wave of nuclear proliferation could ensue, especially if U.S. allies and partners lose faith in America’s commitment to extended deterrence. Mutually assured destruction, which for better or worse has anchored strategic stability since the early 1970s, would be severely stressed in a multipolar nuclear landscape with Russia and the United States fighting at least a proxy war.

Likewise, a broader conflict in Europe would stress, perhaps to the breaking point, the United Nations and many of its auxiliary organizations. Already stymied by a growing rift between the Western permanent members and Russia and China, the Security Council would have failed in its primary reason for being—to prevent the outbreak of a major conflict in Europe. It could continue to exist as a forum for the airing of grievances and acrimonious debate, but it would serve little purpose as a platform for addressing major global issues.

Finally, the humanitarian costs of a wider conflict in Europe would be staggering, particularly given the destructiveness of modern weapons. Beyond the physical destruction and loss of life, untold numbers of refugees would flow across borders not only into Central East Europe but perhaps further West depending on the scale of the fighting. The strain on the socioeconomic systems—coming on top of the stress of the two-year-old pandemic, economic dislocation, and mounting inflation—could bring some close to collapse.

Preventive Options

U.S. policy toward Russia has traditionally been a combination of deterrence and diplomacy. The Biden administration deployed both as it tried to dissuade Russia from invading Ukraine. Both have a role to play in reducing the risk of a wider European conflict, now that Russia has invaded.

Many of the steps that the Biden administration is now taking to counter Russia could be accelerated and expanded to deter it from expanding its military operations beyond that country. They would likely prove more effective due to NATO’s Article 5 collective defense guarantee, which does not apply to Ukraine. The Biden administration could:

  • With its NATO allies, accelerate and expand its current augmentation of forces in vulnerable allies along the frontier with Russia to reassure them—and convince Moscow—of the alliance’s commitment to collective defense.
  • Step up its already intensive schedule of consultations with allies to maintain alliance unity in the face of a burgeoning Russian threat.
  • Develop a long-term plan to reduce Europe’s dependence on imported Russian gas, building on the stopgap measures it is already putting in place to deal with a near-term decision by Moscow to stop flows of gas westward.
  • Consider cutting off energy imports from Russia, and asking the Europeans to do the same, but only after it has prepared the American public for the economic hardship (rising energy costs, inflation) such a step would entail.
  • Accelerate efforts to harden American and allied critical infrastructure against cyber intrusions.

The Biden administration could also resume its diplomatic efforts to find a negotiated solution. To that end, it could:

  • Resist the temptation to cut off channels of communication, as past administrations have done in reaction to Russian aggression. White House−to-Kremlin and military-to-military channels will be critical to reducing misunderstandings that could lead to direct military confrontation between the two countries. In addition, a White House−to-Kremlin link could provide a platform for negotiating an end to the conflict before it spreads beyond Ukraine.
  • Carefully recalibrate its rhetoric to ensure that the confrontation does not turn into an existential one, where victory, whatever that might mean, is the only acceptable outcome. Such a posture would ignore the reality that Russia is unlikely to capitulate in a matter of vital interest—and would escalate rather than surrender. Talk of regime change and possible war crimes charges would probably prove counterproductive and fuel public support for escalation, especially at a moment when polls suggest the war effort enjoys the backing of the vast majority of the Russian population.
  • Avoid appearances that the United States and NATO are waging a conflict against the Russian people. Releasing constructive proposals for resolving the conflict (including provisions for the lifting of sanctions), and urging the Ukrainians to publish reasonable negotiating terms, would be more likely than bellicose warnings to turn the Russian elites and public against the war. Russians need to be persuaded that the United States and Europe are not seeking a punitive peace but are open to a renewal of relations should their country act to end the conflict.
  • Accelerate efforts to get information to the Russian people that would give them a more accurate portrayal of the brutal, unnecessary conflict their leaders are waging allegedly on their behalf. Students and young professionals would be particularly receptive to such information and inclined to protest. 

The mitigating options identified below, with the exception of invoking Article 5, could also be taken now to induce Russia to de-escalate and withdraw from Ukraine and to prevent it from expanding its military operations beyond Ukraine.

Mitigating Options

Should the conflict spread beyond Ukraine despite U.S. efforts, the task will be to bring it to an end on terms favorable to the United States as quickly as possible. Washington could consider diplomatic initiatives, defensive steps, and sanctions.

Diplomatically, Washington could invoke Article 5 of the North Atlantic Treaty to make clear NATO’s determination to come to the aid of members under Russian attack. It could call for an urgent session of the UN Security Council to focus on the threat posed by Russia to international peace and security. The debate would doubtlessly be acrimonious, but the United States needs to make a concerted effort to shape public opinion and isolate Russia as the aggressor. Washington could also propose a P5 (the five permanent members of the UN Security Council: the United States, China, France, Russia, and the United Kingdom) meeting to discuss steps to reduce the risk of nuclear war. To avoid turning this into a two-bloc standoff between Russia and China and the Western powers, India could be added to the discussion. But New Delhi could resist being drawn into an East-West conflict, as it has in the past.

The Biden administration should take care not to provoke severe Russian retaliation or produce spillover effects that cause undue harm to its or its allies’ interests.

With regard to defensive measures, Washington could enlarge NATO de facto to coordinate strategy and tactics with Sweden and Finland, with an eye to their de jure membership in the near future. It could also send a small NATO contingent to the Balkans (Albania, Croatia, Montenegro, and North Macedonia) to warn Serbia and Republika Srpska against aggressive actions against Kosovo and Bosnia-Herzegovina.

Concerning sanctions, Washington could build on the sanctions it had already levied to raise the costs further. However, the Biden administration should take care not to provoke severe Russian retaliation or produce spillover effects that cause undue harm to its or its allies’ interests.


The Biden administration is already taking steps to prevent the spread of conflict in Europe and harden the resilience of allies and partners in the face of Russia’s invasion of Ukraine: further augmentation of NATO forces, including a greater presence of American troops and equipment, along the entire Russia/NATO frontier stretching from the Baltic to the Black Sea; frequent consultations with allies and partners; steps to handle the large-scale exodus of refugees from Ukraine; organization of fuel shipments to Europe from various sources to cover gaps in the event of a Russian cutoff of gas exports; measures to harden U.S. and allied computer networks against attacks. The task is to turn those expedient measures into strategies to fortify the transatlantic community against a prolonged threat from the East, which Russia will continue to pose even if the current crisis is somehow defused in the near future.

In particular, the United States needs to work with its European allies to drastically reduce Europe’s dependence on Russian gas. The goal should be to cut that dependence in half by the end of the decade by fully using the regasification facilities in place, building more, and accelerating work on renewables. In addition, even as the United States and European Union are dealing with the war in Ukraine, they need to recommit themselves to sorting out the continuing problems in Bosnia-Herzegovina and between Serbia and Kosovo to reduce the opportunities for destabilizing Russian interference in the Balkans. Finally, to ease the burden on states bordering Ukraine, the United States should be working with the UNHCR and its allies to develop plans for the long-term resettlement of Ukrainian refugees throughout Europe in case of a long period of instability in Ukraine.

The United States should confront the urgent crisis in Europe without unduly sacrificing focus on the strategic challenge in the Indo-Pacific.

All these steps, however, do not go far enough to deal with the enduring Russia challenge. The Biden administration needs to do more, ideally as part of a larger effort to reposition the United States strategically on the global stage. Critically, the United States should confront the urgent crisis in Europe without unduly sacrificing focus on the strategic challenge in the Indo-Pacific, and to prepare for a major change in the geopolitics of the Eurasian supercontinent. A tall order but not an impossible task.

There are three core elements to this task: rethinking NATO, enhancing the U.S. presence in the Indo-Pacific, and creating a security forum to enhance allies’ support for U.S. policy across Eurasia.

Rethinking NATO. The strategic goal should be the achievement of a near perfect overlap in NATO and EU membership among European states. That would provide the foundation for the development of a united European pillar inside NATO, in a sense resolving the tension between NATO and the EU (if not necessarily between the United States and Europe). The European pillar would assume ever greater responsibility for the defense of the continent, backed up by the American strategic deterrent, thus freeing up American forces to deal with the growing challenges in the Indo-Pacific region.

The alliance’s new strategic concept, to be adopted at the Madrid Summit this coming June, provides an opportunity to articulate this goal, as well as to lay out the full breadth and enduring nature of the Russia challenge. The United States should consider pressing for the following steps:

  • Fortify NATO’s eastern border. The alliance should abandon the pledge of the 1997 NATO-Russia Founding Act not to deploy permanent substantial combat forces to new members. It should augment its forces in vulnerable member states, as long as there is no agreement between NATO and Russia to mutually restrict force levels in border zones.
  • Prepare for the eventual membership of Finland and Sweden to reinforce the northern flank. In the face of Russian conduct, the populations of these two countries are reconsidering their long-standing traditions of neutrality. While staying out of the domestic debate, the United States and other allies should indicate that they would welcome the two countries into the alliance and articulate clearly the changing nature of the security environment in the Baltic region brought on by a more aggressive Russia.
  • Repair relations with Turkey. This is a matter primarily for the United States, which has levied sanctions on its ally for its purchase of S-400s, an advanced Russian air defense system. The United States could take a first step by approving the sale to Turkey of the F-16s it has requested. Washington should also look for an opportunity amidst deteriorating relations with Moscow to persuade Ankara to reconsider its purchase of S-400s.
  • Forego expansion into the former Soviet space for an extended period. No one believes that any former Soviet state will be ready for membership for years to come. Without necessarily abandoning the Open Door policy, the alliance should make clear that it will not expand eastward while it focuses on its own consolidation.

Enhancing the U.S. presence in the Indo-Pacific. In the face of a prolonged conflict in Europe, the United States will still have to expend considerable resources to preserve and advance its interests in the Indo-Pacific. To reassure its allies and partners of its commitment, it will need to maintain, if not increase, the tempo of its military activities, including freedom of navigation operations in the South China Sea; renew its efforts to deter a Chinese invasion of Taiwan; and preserve its military presence in Japan and South Korea. Australian-British-U.S. military cooperation, symbolized by the submarine deal of last fall, should be expanded in the years ahead. At the same time, Washington should continue to deepen strategic cooperation among the Quad. A special effort should be made to enhance strategic cooperation with India and reduce its reliance on Russia for military hardware and nuclear power.

Creating a new security forum. To link its interest in Europe and the Indo-Pacific region, Washington should consider forming a small security forum to enhance allies’ support for U.S. policy across Eurasia. Those partners could include Canada in North America; France, Germany, Italy, Poland, Turkey, and the United Kingdom in Europe; and Australia, India, Japan, and South Korea in the Indo-Pacific region—a new G12 of sorts. The United States could use this forum to underscore its commitment to Europe and the Indo-Pacific region, help its allies in the two regions gain a better sense of their mutual security and economic well-being, and, where possible, coordinate strategies.

One major topic for this forum would be dealing with the growing Russia-China strategic alignment. Conflict in Europe will only push Russia and China closer together, at least initially. But Russia’s aggressive behavior undermines the stability that China requires to build its commercial and technological ties with Europe. The G12 could explore ways its members could exploit and increase this friction to attenuate the Russia-China ties, thereby improving the security situation in both Europe and the Indo-Pacific region.

As the United States repositions itself in the global arena, it will need to come to an understanding with its allies on how it wants a broader conflict with Russia to end. In a prolonged conflict, Moscow will seek to divide the allies in part through calls for peace negotiations. When to negotiate is a delicate question on which the United States and its allies are sure to have different opinions. Washington will have to work hard to forge a consensus. Both victory and defeat will be hard to define. But given the destructiveness of modern weaponry and the ever-present risk of escalation to the nuclear level, a negotiated settlement, in which neither side wins or loses, is to be preferred to pressing for victory—that is, Russia’s capitulation. It should be possible to find one that leaves the transatlantic community stronger and peace in Europe more secure.

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