Sometimes the best way to understand what’s possible is to ask impossible questions.

One year ago, Russia launched a war that many never expected it to wage and assumed it would quickly win against a cowed Ukraine and its allies. How and when will the conflict end? For a war that has defied expectations, those questions might seem impossible to answer. Yet I recently posed them to several top historians, political scientists, geopolitical forecasters, and former officials—because only in imagining potential futures can we understand the rough bounds of the possible, and our own agency in influencing the outcome we want.

The main takeaways from the responses I received? Prepare for the possibility of a long, shape-shifting conflict, perhaps lasting years, even a decade or more. Watch how the rest of the world regards the Kremlin’s imperial ambitions. Expect any negotiated settlement to be fragile and reliant on third-party intervention. And don’t anticipate a dramatic finish, such as a Russian nuclear detonation in Ukraine or the overthrow of Vladimir Putin in Russia. Notably, in a reversal of perceptions a year ago, some experts could envision a decisive Ukrainian victory against Russia, but none forecast a decisive Russian win against Ukraine.

Let’s examine each of these insights in turn.

Beware the fog of war … termination.

First, a meta-point: This exercise is really hard. “No one, including me, has any strong confidence about how or when the war will end,” Dan Reiter, a political scientist at Emory University who wrote an entire book about how wars end, told me.

[Anne Applebaum: It’s time to prepare for a Ukrainian victory]

Wars “proceed in phases,” with “offensives and operational pauses, cycles of increased or decreased intensity in fighting,” and so on; it is perilous to “extrapolate from whatever period you’re currently in and imagine that this will represent the future trajectory” of the conflict, cautioned Michael Kofman, an expert on the Russian military at the Center for Naval Analyses.

There are no certain answers to my questions, just ones contingent on unknowable future circumstances. To put a twist on an old Yiddish expression, people predict, and war laughs.

Prepare for a protracted, protean conflict.

Amid an apparent Russian offensive and anticipated Ukrainian counteroffensives in eastern Ukraine this spring, U.S. officials are reportedly conveying an urgent message to their Ukrainian counterparts: The next several months are crucial to tipping the war in Ukraine’s favor, given that ramped-up Western military assistance can’t necessarily be sustained. Ukrainian leaders and a number of prominent experts argue that Ukraine could actually win the war as early as this year if the United States and its allies speedily provide the types of additional advanced weaponry, such as fighter jets and long-range Army Tactical Missile Systems, that Kyiv is requesting.

If the Ukrainian military were to use such weapons to cut off the land bridge connecting Russia to the Crimean peninsula, which the Kremlin illegally annexed in 2014, Moscow would have a harder time supplying troops and civilians in Crimea and keeping control of it, argued John Herbst, a former U.S. ambassador to Ukraine and the head of the Eurasia Center at the Atlantic Council (where I work). That, in turn, could pressure Putin to strike a peace deal or even bring about new Russian leadership, Herbst told me.

Many experts I consulted, however, advised girding for a struggle that could last a lot longer, even if the war in its more acute form resolves sooner.

The conflict is “already a long war when compared to other interstate conflicts, and wars of this kind tend to cluster as either being relatively short—lasting no more than weeks or a few months—or averaging several years in duration,” Kofman told me. The Center for Strategic and International Studies has found that since 1946, more than half of interstate wars like the one in Ukraine have ended in less than a year, and that when such wars persist for more than a year, they last more than a decade on average.

Any apparent conclusion of the conflict might give way to a reopening of the war in the future, Kofman noted—particularly if the current wave of fighting subsides because of “a premature cease-fire with none of the fundamental issues resolved, and both parties simply use the time to rearm in the hope of returning to the battlefield.”

The forecasting firm Good Judgment’s superforecasters, a global network of about 180 experts in various fields with a strong track record, tend to “see a long slog coming” in Ukraine, CEO Warren Hatch told me. Some of the superforecasters, however, point to key differences between this war and past conflicts that they believe could produce a faster resolution—including the degree to which the West is arming Ukraine and punishing Russia economically.

As of this writing, the superforecasters had assigned a roughly 70 percent probability to the scenario of Russia and Ukraine not agreeing to end the conflict before October 1, 2024, the furthest-out date among the multiple-choice options presented. Good Judgment also posed my questions to its network. When the superforecasters were asked to name the year in which they expected Russia’s war against Ukraine to end, the median answer was 2025, with a minimum of 2024 and a maximum of 2037.

[Phillips Payson O’Brien: Time is on Ukraine’s side, not Russia’s]

The Russian journalist Maria Lipman, now a visiting scholar at the Institute for European, Russian, and Eurasian Studies at George Washington University, observed that at the moment, “neither side seems to have a clear advantage on the battlefield,” and “neither Ukrainian nor Russian leadership is willing to start peace talks.” This leads Lipman to an endgame scenario that some other experts recently have invoked: an armistice akin to that between North and South Korea, with the United States and its allies supporting Kyiv as they do Seoul.

“One may imagine something like the outcome of the Korean War,” with “the warring sides remaining not reconciled and irreconcilable, always on alert, but more or less securely divided,” Lipman told me. Still, she said, whatever border is drawn between Russia and Ukraine is likely to be far longer and harder to secure than the one dividing the Korean peninsula. And Russia, as a much larger country, a permanent member of the United Nations Security Council, and a significant economic player, “is no North Korea” and “can’t and will not be isolated,” she noted.

Michael Kimmage, a historian of U.S.-Russian relations at the Catholic University of America who served on the U.S. State Department’s Policy Planning Staff from 2014 to 2016, told me,  “The one thing I feel comfortable predicting” is that what’s now playing out on the battlefield in Ukraine will prove “a generational conflict” featuring tensions and hostilities over the next two to three decades, even if the current hot war wanes. It will be a conflict between Russia and Ukraine, “but nested within another conflict between the United States and Russia that’s really over Europe at large.”

The closest analogue is the Cold War, when the United States and the Soviet Union took nearly 20 years—until the aftermath of the Cuban missile crisis—to establish “rules of the road” for how to contain and manage the entrenched, multifaceted conflict between the two superpowers, Kimmage argued. In the United States, he noted, everything from industrial policy to diplomatic and military strategy to domestic politics similarly will need to be refashioned for this new conflict. Even as they steel themselves for a long-term contest with China, Americans could find the conflict with Russia becoming more present in their life than it is now—in the form of, say, more Kremlin cyberattacks or election interference, or even direct military confrontation with Russia in a war zone like Ukraine.

Still, Herbst, of the Atlantic Council, noted that the United States is spending only a bit more than 6 percent of its defense budget ($50 billion a year) to support Ukraine militarily and economically, relative to the trillions of dollars that the United States spent over the course of the Cold War. “If leaders explain the stakes and the costs, this is a manageable burden,” he told me.

Keep an eye on whether other countries accept Russia’s claims to empire.

Mick Ryan, a retired major general in the Australian army who now studies the future of warfare, put it plainly: The war is most likely to end “when Putin realizes his imperial fantasies are not possible, and that his army cannot deliver him the victories [on] the ground he needs.”

[From the December 2022 issue: The Russian empire must die]

The Brookings Institution’s Fiona Hill, a senior director for European and Russian affairs on the U.S. National Security Council from 2017 to 2019, also pointed to the Kremlin’s imperial aspirations as a key indicator to watch, but added that these could be thwarted by developments off the battlefield. She doesn’t foresee a durable end to the war in Ukraine until “the world” (here she especially has in mind countries other than the United States and its European allies) “is no longer of the view that Russia deserves a sphere of influence and has a right to empire.” Only in such a scenario, Hill explained, will the Kremlin be prevented from overcoming Western isolation by deepening its diplomatic, economic, and military ties with other countries, and feel international pressure to engage in serious negotiations to end the war through some international framework.

Persuading countries in regions such as Africa and the Middle East to deny Russia its imperial schemes will require a major shift in how the United States and its allies describe the stakes of the war and even in how they articulate their broader worldview, Hill argued. Rather than framing the war as a struggle between democracies and autocracies or East versus West, U.S. and European leaders should make the case that the Kremlin, in its thirst for empire, has “violated the UN Charter [and] international laws” that keep other countries safe as well.

U.S. officials also might need to move away from the strategic paradigm they’ve embraced in recent years of “great-power competition.” This framework, Hill maintained, risks implying that the fates of nations around the world are subject to face-offs among the United States, China, and Russia—and it can shape geopolitical realities rather than merely describing them as they are. The United States might have to push to reform outdated elements of the world’s security architecture, such as the UN Security Council, so that they no longer reflect a bygone era in which a small group of big powers got to determine the course of international affairs.

Anticipate a messy, provisional peace advanced by a group of global actors.

Many experts I consulted were pessimistic about the prospect of a negotiated settlement to end the war in the foreseeable future. But a couple offered scenarios for what such a settlement could look like, portraying them as more guesswork than predictions. Both scenarios involved the mediation of other world powers. Neither featured a tidy, satisfying resolution.

[Eliot A. Cohen: Cut the baloney realism]

Mathew Burrows of the Stimson Center, a former top U.S. intelligence official focused on strategic foresight and global trend analysis, sketched one potential path in which a stalemate leads to a brittle, occasionally violated cease-fire mediated by actors like the United Nations, Turkey, and the United Arab Emirates. Eventually, perhaps if U.S. commitment to Ukraine fades or Putin is weakened by significant opposition during Russia’s 2024 presidential elections, there could be a difficult, lengthy push for a sturdier peace deal involving bigger concessions, with Ukraine encouraged to negotiate by Western and Southern European countries and Russia pressed to do the same by the other “BRICS” nations (Brazil, India, China, and South Africa). That effort would require extensive U.S. involvement as well, and could serve as a springboard for China to assert itself as a diplomatic power, as the United States did during peace talks after World War I.

Reiter, the scholar of how wars end, provided another rough outline: If Russian and Ukrainian offensives this spring fail to result in a clear military victory for either side, a neutral country such as Brazil or India could broker secret peace negotiations. Ukraine and Russia might be more receptive to these diplomatic efforts than before—Putin on account of an exhausted Russian military, Ukrainian leaders out of concern about the war’s mounting economic and humanitarian toll and the slackening of Western military assistance. The talks could yield a shaky cease-fire in which Russia consented to remove its forces from Ukrainian territory (a commitment that all parties think the Kremlin will probably renege on by maintaining a military presence in the country’s east) and Ukraine vowed to reestablish a water supply to Crimea without recognizing Russia’s annexation of the peninsula. The agreement also could include a tacit understanding that Ukraine would not formally join NATO. Such a deal could provide Putin with a “fig leaf” to “declare victory for domestic political audiences” and enable Ukraine to begin postwar reconstruction, Reiter reasoned. But it would leave the core issues of sovereignty that triggered the war unresolved.

Don’t expect the war to end in a mushroom cloud.

Over the past year, there has been an ebbing and flowing fear of the war in Ukraine ending apocalyptically, with Russia resorting to the use of nuclear weapons, stirred most recently by Putin suspending cooperation in the nuclear-arms-control treaty with the United States known as New START. But many experts I turned to were not seriously concerned about such an outcome.

[Eric Schlosser: The greatest nuclear threat we face is a Russian victory]

In explaining why, Reiter pointed to “the heavy diplomatic costs of [Russia] using nuclear weapons, the lack of military utility of using nuclear weapons,” and the risk that such use would “increase NATO military involvement” in the war. Timothy Snyder, a historian of Eastern Europe at Yale, told me he stands by an assessment he made in October in which he similarly argued that a Russian nuclear detonation was highly unlikely. “We are drawn to this scenario, in part, because we seem to lack other variants, and it feels like an ending,” he wrote at the time. More likely, Snyder argues, Putin is trying to instill fear in order to buy his military time and undermine international support for Ukraine.

And don’t assume that the war will conclude with regime change in Moscow.

When my colleagues at the Atlantic Council and I recently surveyed more than 150 global strategists and foresight experts about what the world could look like in 10 years, nearly half of the respondents expected Russia to either become a failed state or break up internally by 2033, presumably driven at least in part by Putin’s disastrous war against Ukraine. But even if this occurs, that doesn’t mean the war itself will end with Putin’s downfall.

In his October assessment, Snyder floated one scenario in which Ukrainian military victories prompt a power struggle in Moscow that leads Russia to withdraw from Ukraine, as Putin and his rivals judge that the armed forces loyal to them are most useful on the homefront. But what Snyder envisions is Putin prioritizing his political survival in Russia over his personal and ideological designs on Ukraine, not necessarily Putin’s removal from power.

Kofman, at CNA, considers “leadership or regime change in Russia” to be “unlikely in the near term,” and pointed out that “a change in leadership will not necessarily lead Moscow to end the war.” Kimmage, at Catholic University, estimated that the odds are “one in a thousand or one in a million” that a new Russian leader will emerge who is willing to withdraw Russian forces from all Ukrainian territory, subject Russian perpetrators to war-crimes tribunals, and pay reparations to Ukraine—all objectives Kyiv has articulated.

Lipman, the journalist and scholar, expects “a long period of decline or decay in all spheres of life” for Russia, but she currently doesn’t foresee political upheaval. Putin’s “grip on power has grown even tighter and his authority even more unlimited” over the past year, with broad “public acquiescence” to the war and Russian elites still relying on Putin for “security and stability,” she noted. “Will the situation change to a point when taking the risks to oppose Putin may appear justified? That’s something very hard to imagine, looking from today. Right now, pledging full allegiance certainly appears to be a safer strategy.”

Kimmage, for his part, worries that the United States and its allies might expect a “Hollywood version” of the war’s ending, featuring Ukrainian President Volodymyr Zelensky as “the David who’s going to beat Goliath.” The danger, he said, is that “if there’s too much of an expectation of quick-fix, instant-gratification heroism … we’ll end up getting frustrated with Zelensky and the Ukrainians” and then could wind down support for their struggle. Zelensky “deserves all the praise he gets, but the script is not written. And the script is not destined to have a happy ending. And it’s not destined to have a happy ending soon if there is a happy ending,” Kimmage explained. “We have to build a narrative of the war that’s durable enough that it doesn’t depend on that happy ending.”