WITH THE Cold War’s demise, the menacing Russia that long loomed over Europe seemed to vanish. The Russia of 1992 was just a fragment of its historic self in military punch and economic weight. Not even Russia’s still-formidable nuclear arsenal deflected perceptions of decline. It was inevitable, then, that Western policy makers would feel that this shrunken Russia was more to be ignored than feared. They were wrong.

Now, memories of the bad old days are storming back, especially of Moscow’s capacity to stir up trouble with its military power. While President Vladimir Putin’s “covert” war in Ukraine continues to inflame tensions, he also torments his Baltic neighbors and threatens Europe with provocative military flights and nuclear rhetoric. Western alarms are heightened by Putin’s seeming unpredictability and his apparently unlimited internal power. The West can’t reckon how far he will take his muscle flexing—or how to stop him.

NATO has no strategy to counter mounting Russian pressures. Economic sanctions, the West’s spear point, have seriously harmed the Russian economy, enough to squeeze from Putin some dubious cease-fire agreements on Ukraine, but not nearly enough to make him back down. Europeans are reluctant to expand sanctions for fear of prompting a Russian military response and for fear of further complicating their dependence on Russian oil and gas. On the military side, NATO has deployed mostly American fighter jets eastward and stepped up joint exercises and arms deliveries. Unsurprisingly, European NATO allies do the minimum militarily, and instead press ahead with a weak diplomatic hand. This diplomatic impotence is so pronounced that President Barack Obama has distanced himself from it, preferring to let the Germans take charge.

The reason for the West’s limp hand is painfully evident to all: Russia’s military superiority over NATO on its western borders. If NATO ups the military ante, Moscow can readily trump it. Moscow has significant advantages in conventional forces—backed by potent tactical nuclear weapons and a stated willingness to use them to sustain advantages or avoid defeat. The last thing NATO wants is to look weak or lose a confrontation.

NATO’s military and civilian officials have worried about this situation for several years now—without receiving much productive guidance from their capitals. Predictably, a growing chorus in America (and not just the usual hawks) is championing sending weapons to Ukraine. Just as predictably, these advocates say nothing about what they would do if Moscow’s response were to escalate.

Thus, NATO’s options have narrowed: more arms aid to beleaguered friends, but no answers to Russian escalatory responses; more sanctions that hurt but don’t humble Russia’s economy; calls for a major NATO military buildup in Eastern Europe with no prospect of realization; and more diplomacy without leverage.

What, then, can the West do that has some chance of success? The only sensible path is to develop a diplomatic strategy with real leverage. This strategy would retain the sanctions regime and credible prospects for a greater NATO presence until its benefits materialize. It is now quite evident, however, that these punitive and defensive measures alone won’t produce the requisite power over Russia, a conclusion shared by a number of former American ambassadors to Moscow, including Jack Matlock, Thomas Pickering and James Collins.

An effective diplomatic strategy has to be rooted in what matters most to Russian leaders—their historical sense of self and their passion to be treated as a great power. Moscow deserves no less, given the troubles it can cause and the problems it can help resolve. The West need not silence its complaints about the Kremlin’s brutality, nor concede vital interests. It is totally unrealistic, however, to think that the West can gain desired Russian restraint and cooperation without dealing with Moscow as a great power that possesses real and legitimate interests, especially in its border areas.

The strategy proposed here should be thought of as Détente Plus. It would pick up from the détente diplomacy of the past and go well beyond it. The old détente was about managing serious conflicts of interests and values with a mostly implacable foe. Détente Plus would not treat Russia as an enemy, but as a combination of adversary and partner. Détente Plus would exceed the arms-control focus of the past and address first-rank political matters in Europe and worldwide. It would recognize a wide range of common and overlapping interests, solving both Russian and American problems.

This cooperation has to be visible, filled with optics. Call it mountaintop diplomacy. The world would be watching as the two powers devised common solutions to common problems.

American and Western leverage would stem from the visibility and the results generated. Being seen at the mountaintop with the United States would go far toward satisfying Russia’s yearning for status. To maintain this status, Kremlin leaders would understand their need to bend, but status is not enough. Moscow would have to benefit tangibly as well, mainly in improved economic prospects and assuaged political concerns.

With this leverage, Washington can do two things: first, tame Russian assertiveness and secure Russia’s restraint on its western border; second, and often overlooked, step up joint action based on common interests on other critical fronts such as terrorism, Syria, Iran and nuclear proliferation. Today’s pervasive atmosphere of hostility and mistrust obscures these promising possibilities. Given the dangers ahead and the poor alternatives for dealing with them, the Détente Plus strategy deserves a trial.

JUST IMAGINE if the United States had lost the Cold War. For some comparative measure, think about the American trauma after losing the Vietnam War and after the inconclusive battles over many years in Afghanistan and Iraq. Yet most Americans won’t give an inch when it comes to recognizing the far greater trauma for Russians after their utter defeat in the Cold War and NATO’s almost immediate march eastward to their borders. Those profound shocks are central to fathoming recent Russian provocations and key to combating them. That’s why it is essential to consider Russian history since the collapse of the Berlin Wall, not to justify Putin’s course, but to comprehend it.

Across Eastern Europe, Communist dictatorships collapsed in short order and were swiftly replaced by democratically elected governments that looked west for their future. As Czech statesman Vaclav Havel remarked, “We have had literally no time even to be astonished.” Germany reunified and became a leading member of the Western club virtually overnight. Mikhail Gorbachev exercised considerable restraint as the outer empire collapsed around him, but the experience could hardly have been more distressing for his nation. Soviet troops were compelled to withdraw haphazardly from Eastern Europe and surrender, without a shot fired, the very territories that millions of Soviet soldiers had died to secure and dominate just decades earlier.

Conservative critics in the Communist Party and in the military understood the perilous course upon which Gorbachev’s reforms had set the Soviet Union, but remained divided on what to do about it. In August 1991, a faction of the conservatives attempted to oust the premier in a coup, but it was too little, too late. Soviet patriots like Chief of the General Staff Sergei F. Akhromeyev and Interior Minister Boris K. Pugo committed suicide rather than face the death of their country.

Within months of the coup, the Soviet Union collapsed, breaking into fifteen weak republics. As a rump state, Russia lost a quarter of its territory, half of its population and much of its wealth. Russians especially lamented the loss of territories like Ukraine that were integral to Russia’s history and identity. The formerly colossal Soviet military was devastated as the post-Soviet republics began nationalizing the forces and materiel stationed within their borders. In 1991, the USSR had nearly four million men on active duty and could mobilize up to ten million. The system designed to win World War III was too weak to save itself.

Compounding Russia’s sense of crisis, the peripheral republics of the Soviet Union erupted with terrible ethnic, nationalist and religious violence as the Communist edifice crumbled from the center. Intense fighting gripped Central Asia, the Caucasus and Moldova. Even the Baltic republics succumbed to violence in their struggle to secede from the USSR. While the Soviet Union lasted, its forces were sent in to try to restore order and stymie budding independence movements, often counterproductively.

Even after 1991, Russian troops remained engaged in battles along the country’s southern frontier. Moscow’s concern was that these nationalist, religious and ethnic convulsions could prove contagious. If unchecked, they would threaten a multiethnic and multiconfessional Russia. This fear proved well founded in Chechnya, where the Russian army was humiliated by guerrilla fighters between 1994 and 1996.

Given the chaos gripping Russia, it was hardly surprising that Western leaders began to write off Moscow’s interests in ways unimaginable just a few years before. When Chancellor Helmut Kohl suggested to President George H. W. Bush in 1990 that Moscow should get something in return for its acquiescence to the reunification of Germany, the president responded, “To hell with that! We prevailed, they didn’t. We can’t let the Soviets clutch victory from the jaws of defeat.” The Russians felt this disdain acutely, and their frustration mounted as the West pressed its advantages over the next two decades in what appeared to be an attempt to encircle Russia.