The brute fact that Latvia is a member of the NATO alliance is hard to ignore. The United States and other members have solemnly pledged themselves to regard “an attack upon one as an attack upon all.” But will German troops come to Latvia’s rescue? And if they did, would a majority of Germans support that action? Would the French, or British? Would Americans?

If we do, we will cross a bright redline Republican and Democratic presidents assiduously avoided over four decades of Cold War: American and Russian troops would be killing each other. Any such conflict would raise risks of escalation in which each nuclear superpower remains capable of erasing the other from the map. But if we don't, we will see a precipitous collapse of the credibility of U.S. security guarantees that have been the central pillar of the international security architecture the United States has constructed since World War II. Not only European allies, but Japan, South Korea, and others who have staked their survival on a U.S. security umbrella will look to their own defense.

In highlighting downside dangers in the current drift of events in Ukraine, my argument is not that these are the most likely outcomes. If Putin thinks first about Russian national interests, he will have sufficient reason to cooperate in preventing Iran acquiring a nuclear bomb. From the perspective of Russian national interests, acquiring additional territory in Eastern or Southern Ukraine and seeing the emergence of autonomous republics dependent on substantial financial support from Moscow is hardly a beneficial outcome for Russia. The overwhelming majority of Russians in the Baltics know that their lives are better as members of independent European states than they would be as provinces of Russia.

Nonetheless, especially in managing relations between great powers, and most especially, nuclear superpowers, American Cold War statesmen were vigilant in analyzing worst-case scenarios. Recognizing extreme risks (extremely unlikely, but extremely consequential), they observed what JFK, in the aftermath of the Cuban missile crisis, called “primitive rules of prudence.” These accepted constraints and compromises in a competition in which the ultimate objective for each was to bury the other. Thus, Eisenhower refused to come to the rescue of Hungarian freedom fighters in 1956; LBJ to support the Prague uprising in 1968; and Reagan to deny overt support for Polish Solidarity and others as they loosened the Soviet grip on the Warsaw Pact.

If the likely outcome on the current path is unacceptable, or poses unacceptable risks, are there alternatives that, however ugly, are nonetheless preferable to what is otherwise likely to happen? I believe the answer is yes. Imagine an agreement in which all of the territory of Ukraine (minus Crimea) remains a sovereign, independent nonbloc state. In military and economic relations, Ukraine would agree with all the parties that it would remain neutral for the next quarter-century. It would thus not become a member of NATO or the European Union, nor of equivalent Russian-led institutions. Internally, it would make a commitment to meet the highest EU standards for guaranteeing minority rights, including those of Russian speakers. And as an integral part of this package, all parties would also commit themselves to provide specific support for the new government of Ukraine as it attempts to build a viable state. For historical analogies, think Belgium in the nineteenth century, or Austria after World War II, or Finland.

Obviously, such an agreement could not be imposed on Ukraine. Its government will have to be a willing party to any resolution and convinced that it is preferable to its feasible alternatives. Realistic Ukrainians know, however, that Ukraine’s survival as an independent political entity will prove impossible without Russian forbearance. Indeed, for the foreseeable future, Ukraine’s economic viability will depend on Russian financial assistance (through below-market gas prices and delayed collection of outstanding debt for earlier deliveries), continuing exports of essential raw materials, and imports of Ukrainian products—all of which Russia can withhold at its own discretion.

Obviously, such an agreement would not be fair. But as JFK often observed, “life is unfair.” Ukraine is free to choose between claiming all the rights and privileges of a normal modern state and ending up with half its current territory, or meeting enough of a Russian bully’s demands to have a chance to survive with its current borders and, if it succeeds, to put Putin to shame.

An agreement requiring so much compromise by all parties will strike most readers as implausible—and is surely unlikely. Politically, the smart move for all the Western leaders is to focus their fire on Putin, unquestionably a most deserving target. But for those of us who still believe that Ukraine can have a future, this week’s decision by the IMF to release the first $3 billion of a $17 billion emergency rescue package to prevent the country from default and forestall economic collapse keeps hope alive. Despite the neo–Cold War divide with Russia on every other issue concerning Ukraine, the IMF was able to pull the package together quickly and win approval for it only because of cooperation from all the parties—including Putin’s Russia.

Graham Allison is director of the Harvard Kennedy School’s Belfer Center for Science and International Affairs.

Image: U.S. Air Force Flickr.