Russia’s invasion of Ukraine in February 2022 was a moment of clarity for the United States and its allies. An urgent mission was before them: to assist Ukraine as it countered Russian aggression and to punish Moscow for its transgressions. While the Western response was clear from the start, the objective—the endgame of this war—has been nebulous.

This ambiguity has been more a feature than a bug of U.S. policy. As National Security Adviser Jake Sullivan put it in June 2022, “We have in fact refrained from laying out what we see as an endgame. . . . We have been focused on what we can do today, tomorrow, next week to strengthen the Ukrainians’ hand to the maximum extent possible, first on the battlefield and then ultimately at the negotiating table.” This approach made sense in the initial months of the conflict. The trajectory of the war was far from clear at that point. Ukrainian President Volodymyr Zelensky was still talking about his readiness to meet his Russian counterpart, Vladimir Putin, and the West had yet to supply Kyiv with sophisticated ground-based rocket systems, let alone tanks and long-range missiles as it does today. Plus, it will always be difficult for the United States to speak about its view on the objective of a war that its forces are not fighting. The Ukrainians are the ones dying for their country, so they ultimately get to decide when to stop—regardless of what Washington might want.

But it is now time that the United States develop a vision for how the war ends. Fifteen months of fighting has made clear that neither side has the capacity—even with external help—to achieve a decisive military victory over the other. Regardless of how much territory Ukrainian forces can liberate, Russia will maintain the capability to pose a permanent threat to Ukraine. The Ukrainian military will also have the capacity to hold at risk any areas of the country occupied by Russian forces—and to impose costs on military and civilian targets within Russia itself.

These factors could lead to a devastating, years-long conflict that does not produce a definitive outcome. The United States and its allies thus face a choice about their future strategy. They could begin to try to steer the war toward a negotiated end in the coming months. Or they could do so years from now. If they decide to wait, the fundamentals of the conflict will likely be the same, but the costs of the war—human, financial, and otherwise—will have multiplied. An effective strategy for what has become the most consequential international crisis in at least a generation therefore requires the United States and its allies to shift their focus and start facilitating an endgame.

WHAT WINNING DOESN’T LOOK LIKE

As of the end of May, the Ukrainian military was on the verge of conducting a significant counteroffensive. After Kyiv’s successes in two earlier operations in the fall of 2022, and given the generally unpredictable nature of this conflict, it is certainly possible that the counteroffensive will produce meaningful gains.

 

Western policymakers’ attention is primarily devoted to delivering the military hardware, intelligence, and training necessary to make that happen. With so much seemingly in flux on the battlefield, some might argue that now is not the time for the West to start discussions on the endgame. After all, the task of giving the Ukrainians a chance at a successful offensive campaign is already straining the resources of Western governments. But even if it goes well, a counteroffensive will not produce a militarily decisive outcome. Indeed, even major movement of the frontline will not necessarily end the conflict.

More broadly, interstate wars generally do not end when one side’s forces are pushed beyond a certain point on the map. In other words, territorial conquest—or reconquest—is not in itself a form of war termination. The same will likely be true in Ukraine: even if Kyiv were successful beyond all expectations and forced Russian troops to retreat across the international border, Moscow would not necessarily stop fighting. But few in the West expect that outcome at any point, let alone in the near term. Instead, the optimistic expectation for the coming months is that the Ukrainians will make some gains in the south, perhaps retaking parts of the Zaporizhzhia and Kherson regions, or push back the Russian assault in the east.

Those potential gains would be important, and they are certainly desirable. Fewer Ukrainians would be subjected to the unspeakable horrors of Russian occupation. Kyiv might retake control of major economic assets, such as the Zaporizhzhia Nuclear Power Plant, the largest in Europe. And Russia would have suffered another blow to its military capabilities and global prestige, further raising the costs of what has been a strategic catastrophe for Moscow.

The hope in Western capitals is that Kyiv’s gains on the battlefield will then force Putin to the negotiating table. And it is possible that another tactical setback would diminish Moscow’s optimism about continued fighting. But just as losing territorial control does not equate to losing a war, neither does it necessarily induce political concessions. Putin could announce another round of mobilization, intensify his bombing campaign on Ukraine’s cities, or merely hold the line, convinced that time will work for him and against Ukraine. He might well continue fighting even if he thinks he will lose. Other states have chosen to keep fighting despite recognizing the inevitability of defeat: think, for example, of Germany in World War I. In short, gains on the battlefield will not in themselves necessarily bring about an end to the war.