Nearly eight years after Russia invaded Ukraine and illegally annexed Crimea, triggering a raft of international sanctions, the United States and its allies find themselves again trying to figure out how to deter Moscow from menacing Ukraine—if not launching a full-scale invasion—in hopes of gaining new Western concessions. Talks between U.S. President Joe Biden and Russian President Vladimir Putin have begun in earnest, with Putin putting forth maximalist demands that could become either the starting point for protracted negotiations that meet somewhere in the middle or, if left unmet, the pretext for a major escalation in the ongoing conflict.

U.S. and European leaders have warned Putin publicly and privately that should he again launch military forces into Ukraine, they will not hesitate to expand sanctions against Russia. U.S. National Security Adviser Jake Sullivan reported that during a two-hour videoconference with Putin on December 7, Biden warned the Russian leader that “things we did not do in 2014 we are prepared to do now.” Biden’s threat to his Russian interlocutors left little room for misunderstanding.

Yet economic sanctions alone, no matter how personally painful they may be to Putin and his cronies, will not be enough to prevent the Kremlin from using tactics that have proved effective in the past. In the years since Russia’s last major confrontation with the United States and its allies, Putin has been honing his skills at intimidation, using military mobilizations, disinformation campaigns, and conflict below the threshold of war to terrify his neighbors and keep the West perpetually on edge. When it comes to sanctions, Putin’s pain threshold is very high and his political resilience appears bulletproof. He is increasingly confident that he will outlast his Western adversaries—and, indeed, none of the foreign heads of state who pushed to sanction Putin after his Crimean adventure remain in office.

To deter Putin, Washington and its partners must persuade him that his provocations will also be met with a military response that will weaken the impact of his favorite coercive tactics and dramatically undermine Russia’s ability to strong-arm concessions from its neighbors. By strengthening their military capabilities in Europe and increasing their presence along Russia’s periphery, the United States and its allies can both shore up neighboring governments’ confidence in their ability to withstand Russian bullying and shake Putin’s confidence that his Western adversaries lack the means and the will to resist his aggression.


Russia’s initial invasion of Ukraine came as a shock to the United States and its allies. The alliance’s focus on territorial threats to European allies had atrophied in the years since the 9/11 attacks. It was during a February 2014 meeting that I attended of NATO defense ministers in Brussels that rumors of “little green men” infiltrating Crimea were first heard and greeted with disbelief by the assembled NATO leaders. In the hours that followed, we scrambled to find accurate information about what was taking place in Crimea.

Still grappling to understand Putin’s intent, though beginning to recover from the shock, the United States and its allies started putting together a raft of measures designed to punish Russia for its actions and to deter future aggression: a package of economic and financial sanctions that sought to punish Putin without further provoking him, and while limiting any impact on Western interests. The resulting halfhearted measures had little coercive effect on Putin; meanwhile, Western countries limited their military assistance to Ukraine to nonlethal support only. 

Putin has been using conflict below the threshold of war to terrify his neighbors and keep the West on edge.

However, Putin’s aggression prompted the United States and NATO to begin a crash program to strengthen military deterrence in Europe, which had been weakened by years of U.S. troop withdrawals, base closures, and deep cuts in allied defense spending. In order to reassure allies of its commitment to defend NATO, the United States began to deploy forces back into Europe. This time, U.S. forces would go on a rotational basis—not as permanent deployments to European bases, as they had during the Cold War. Two armored brigade combat teams (ABCTs) deployed on nine-month rotations to Germany to train with allied troops on the frontlines from the Baltic to the Black Sea. NATO also strengthened its rapid reaction forces and deployed multinational battle groups to the Baltic countries and Poland to act as tripwires in the event of a Russian incursion. The United States pushed its allies to increase their spending on defense, which they did. Slowly, Washington was restoring confidence among frontline allies that they would not be left to face Russian intimidation alone.

But what the West didn’t do in 2014 was rearm the Ukraine military with the kind of lethal military equipment it would take to stand up to Putin and give him pause when considering another invasion. Washington did not want to provoke Putin or risk steering him away from diplomatic efforts. Although the United States and other countries sent millions in funding, nonlethal equipment, and training teams to Ukraine, they declined to deploy combat troops or battle groups, as they did to NATO members in the Baltics and Poland. The limited military assistance to Ukraine taught Putin that NATO would go only so far to defend a non-NATO ally such as Ukraine: he could harass his neighbors with virtual impunity because the United States and its allies were not eager to go to war for a non-NATO ally.


As talks get underway between Putin and the West, the Kremlin is undoubtedly considering the lessons of 2014 as it assesses the potential costs of another invasion of Ukraine. As in 2014, the United States and its NATO allies have offered strong rhetorical support for Ukrainian sovereignty but, again to avoid provoking Russia as talks begin, have yet to send significant lethal assistance to the country or to strengthen forces already deployed to allied countries along the frontier with Russia.   

If next week’s meeting in Geneva between U.S. and Russian officials shows that the Russians are interested not in de-escalation but in using the talks to build a case for hostilities, then the United States and the West should lose no time in quickly providing lethal military assistance to Ukraine, including additional training by U.S. and NATO forces. The United States could preposition equipment for an ABCT in western Ukraine, similar to the sets prepositioned in allied nations, to assist the United States in training Ukrainian forces. American boots and armor on the ground in Ukraine, even as trainers, would create a tripwire that would complicate Kremlin planning by risking a direct confrontation with the United States—something that Putin does not want.   

To deter Russia from continuing to intimidate other European nations, the United States and its NATO allies must make it clear to Putin that this time he has good reason to expect a NATO response that includes significant military reinforcement of Europe to strengthen the confidence of Russia’s neighbors and so reassure them that they are no longer quite so vulnerable to manipulation by Russian military threats.

This buildup of U.S. and allied forces could include returning U.S. and allied air force combat squadrons to long-shuttered but now reopened European bases, bolstering allied ground forces deployed permanently to Europe with additional armor and missile defense batteries, and reinforcing the U.S. Navy’s Sixth Fleet with a carrier strike group rotation and destroyer rotations to ports in northern Europe. If Washington and its allies took those steps, European security would be significantly strengthened, and Putin might recalculate how easy it is for him to use military intimidation to manipulate others.

Continued Russian provocations have made it clear that the Western allies’ economic sanctions on Russia after its 2014 invasion of Ukraine not only were an inadequate deterrent but may actually have given Putin a sense of impunity. A new package of even harsher economic sanctions will help, but only if it is accompanied by a robust military response. Sanctions alone cannot break the cycle of intimidation and capitulation that keeps so many citizens of former Soviet bloc countries in Putin’s thrall. Putin’s favorite tool of military intimidation must be undermined by a renewed U.S. and NATO military posture in Europe that inspires confidence in those nations under pressure and so strengthens them to withstand Putin’s provocations.

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  • JIM TOWNSEND is an Adjunct Senior Fellow at the Center for a New American Security. From 2009 to 2017, he served as U.S. Deputy Assistant Secretary of Defense for European and NATO Policy.
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