Congress has finally approved around $61 billion in new aid to Ukraine, and something strange has happened: Talk of Ukrainian victory has returned to Washington. It’s a jarring turnabout. For the last few months, the White House and others issued dire warnings that if left unaided, Ukrainian lines might collapse and Russian troops might again roll on Kyiv. But with the worst averted, sights are setting higher. The Biden administration is now working to build up the Ukrainian Armed Forces over a 10-year period, at a likely cost of hundreds of billions of dollars, while National Security Advisor Jake Sullivan suggested that Ukraine would mount another counteroffensive in 2025.

This optimism is misplaced. The new bill may well represent the last big package that the United States will send to Ukraine. As the geopolitical analyst Ian Bremmer noted, “America continuing to send Ukraine [$]60 billion in support year after year [is] unrealistic no matter who wins the presidency.” Current aid will mostly help to put Ukraine in a better position for future negotiations. It will ameliorate shortfalls in ammunition and weaponry, making it less likely that Ukrainian forces will lose more ground in coming months. Yet Ukraine still faces other challenges: insufficient fortifications, a yawning manpower shortage, and a surprisingly resilient Russian army. On the whole, Ukraine remains the weaker party; Western assistance has not altered that reality.

The White House presented the supplemental as an all-or-nothing choice: Approve billions in funding or watch Ukraine go under. Such rhetoric contains eerie echoes of wars from Vietnam to Afghanistan, where the United States kept pouring resources into lost causes at least in part because no U.S. leader wanted to be held responsible at the final moment of failure. Throughout the Ukraine aid debate, key questions were left entirely unanswered: What is the United States trying to achieve in Ukraine given that total victory is not feasible? What is it willing to risk and spend to get there? The supplemental punts these uncomfortable questions down the road. But if Washington doesn’t confront them, it may end up back in the same position next year—or worse.

The matter of an endgame in Ukraine has always been fraught. Political scientists have frequently noted that any end to this war will include diplomatic negotiation. Some draw the conclusion that if negotiation is inevitable, talks should begin sooner rather than later. Others argue that Ukraine must improve its battlefield position before negotiating. The government in Kyiv maintains that Russia must be driven completely out of Ukraine, including Crimea, before talks can begin. Some even argue that regime change in Moscow is a precondition for peace.

The squishy middle of the Washington debate, which seems to include senior members of the Biden administration, falls somewhere between these extremes: hoping for major Ukrainian advances, while avoiding escalation and acknowledging privately or anonymously that the math is not in Kyiv’s favor. The White House is correct that aid should be designed to put the Ukrainians in a strong negotiating position. But this raises further questions: How should one determine when the moment for negotiations has arrived? If Ukraine keeps fighting without talking, will its bargaining power improve or diminish?

The calculation is also complicated by confusion about what the United States is trying to achieve in Ukraine. Some emphasize broad, universal principles such as defending democracy or protecting the international order. These are laudable goals, but they could plausibly produce opposite conclusions: either that universal principles have already been adequately defended—the steep price Russia has paid could dissuade future aggressors—or alternately that Ukraine must score a definitive victory.

More hard-nosed analysts instead argue that America’s primary goal in arming Ukraine is to bleed Russia. Keeping up the flow of Western weapons, they argue, allows the West to diminish Russia’s military capabilities at a reasonable cost. As an objective, however, weakening Russia offers no endgame, and implies a long-term, semipermanent commitment to war. Given Russia’s ability to reconstitute its forces, it is not even clear the West is succeeding on this front.

A final group offers more concrete goals: enabling Ukraine to retake specific chunks of territory so as to protect its economic viability as a sovereign state, or to prevent Russia from seizing Odesa and other valuable places. But although these are more specific objectives, there is no consensus on them in Western capitals and little willingness to push for peace negotiations once they are achieved.

This is perhaps why White House officials return so often to the formulation that Western aid is simply intended to put Ukraine in the best possible position at the bargaining table. Saying this requires no difficult decisions about the territory Ukraine needs to retake and no consideration of how long Western aid should continue. It also evades the question of Ukraine’s future orientation—will it join the EU or NATO?—which may need to be resolved in order to end the war.

In short, the current approach is a strategic cop-out. Its primary benefit is to paper over differences among Ukraine’s supporters. The risk is that the war will join the ranks of forever wars and end in one of three ways: in defeat, on worse terms than could have been obtained earlier, or on the same terms at a higher human and financial toll.

“Forever war” became a slogan over the past decade-plus, used by activists to describe the seemingly endless American deployments overseas in complex wars from Afghanistan to Syria and Niger. Like all slogans, the term was imprecise, but it crisply conveyed the problem of waging open-ended conflicts aimed at absolute, unachievable victory.

The conflict in Ukraine should not be directly compared to the wars in Afghanistan and Iraq: No U.S. troops are engaged in combat, and the government of Ukraine is fighting an illegal invasion. Still, there are parallels. Once the Afghanistan surge failed, the debate pitted those who argued that the conflict could not be won against those who argued that it could be sustained at a low enough cost indefinitely. Today’s Ukraine debates have begun to trend in that direction. Sen. Mitch McConnell, among others, has argued that aiding Ukraine is a bargain in defense terms and pumps money back into the U.S. economy.

The common link between Ukraine and past forever wars is thus the way genuine strategic debate gets evaded or stigmatized. Lawmakers and policymakers find it easier to sustain the war effort by presenting a succession of all-or-nothing choices than to look ahead and weigh realistic alternatives.

Proponents of either disengagement or escalation fill the vacuum left by ill-defined or unattainable goals. The former proved surprisingly successful in holding up U.S. assistance for six-plus months. The latter camp, meanwhile, is ascending. After all, if the present trajectory is unfavorable and adopting more limited aims is ruled out, policymakers will seek the other logical solution: that of expanding involvement in the conflict.

The West has gradually escalated over the past two years, as has Russia. Since the beginning of the full-scale invasion, Ukraine and its Western supporters have pushed for ever more advanced weapons. From support vehicles to tanks, tube artillery to ATACMS, the cycle was consistent: As soon as the White House approved one system, pressure would mount to supply the next. A similar trend played out in Europe. Yet with the third year of the conflict underway, technological exhaustion is imposing an upper limit on this trend. In many areas, there is now no “next system” to send.

This dynamic helps explain the recent discussion of more intensive forms of involvement. Just last week, British Foreign Secretary David Cameron told reporters that Ukraine could use British-provided weapons to strike targets inside Russia. French President Emmanuel Macron renewed his recent suggestion that he might send troops to Ukraine to serve in behind-the-lines roles. Each of these was a distinctly escalatory proposal that even six months ago would not have happened. On Monday, citing the British and French statements, Russia announced it would hold drills to practice the battlefield use of tactical nuclear weapons.

Another proposal, which the Department of Defense is reportedly considering in some form, is to send greater numbers of U.S. military advisors to Ukraine to provide maintenance support, training, and tactical advice. This is likewise portrayed as a middle step between the status quo and entering the conflict directly. But it’s also dangerous, creating the potential for direct conflict with Russian forces should advisors be killed or wounded. Russia, for its part, may view the measure as a precursor to greater Western involvement and escalate in turn. The experience of the Vietnam war—where advisors proved to be steppingstones to full combat—ought to serve as a warning.

Of course, the intent of recent calls for intensified Western involvement is to improve the balance of power between Ukraine and Russia. But if a vast infusion of Western technology over the last two years has not resolved Ukraine’s weakness vis-à-vis Russia, then neither advisors nor behind-the-lines support would likely change this dynamic.

For all the effort the Biden administration has put into delivering aid to Ukraine, it has also set U.S. strategy on autopilot. There appears to be no plan other than to try to keep the money flowing—the new aid could last as little as six months or as long as 18 months—which will work until it doesn’t.

Instead, the administration should publicly acknowledge that Ukrainian and American interests are not identical and that Kyiv’s stated aim of liberating every inch of Ukrainian territory is not realistically achievable. America’s most important interests are to safeguard Ukraine’s existence as a sovereign state and to avoid direct conflict with Russia. Each of these should take priority over the further liberation of territory.

Accordingly, U.S. leaders should encourage and incentivize Ukraine to prioritize defense over offense, a process that is already beginning. The last two years have demonstrated the ability of defenders to hold off motivated and more numerous attackers; both sides have experienced slow advances and limited gains when facing dug-in opponents. Washington should channel its assistance into ensuring Ukraine can protect itself, which means more basics like ammunition and fortifications and fewer high-tech offensive systems like ATACMS. It should also help Ukraine to rebuild its military-industrial base.

No less important, the time has come to encourage negotiations between Ukraine and Russia. If Ukrainian forces, buoyed by new aid deliveries, can stabilize the front line, then the summer of 2024 may prove to be a favorable negotiating window. Up to this point, the Biden administration has been wary of pushing Ukraine to negotiate for fear of appearing to signal a lack of U.S. commitment. In addition, negotiations can be slow, and Russia may not yet be willing to participate in earnest. But the proposition has not been tested, and it is worth trying, particularly because punting the decision to Kyiv, while supplying it with arms, has the perverse effect of discouraging Ukraine from talking. Neither side can truly gauge what it could obtain until it starts talking to the other, and recent revelations about prior negotiations between Kyiv and Moscow suggest that a settlement is not impossible.

Finally, Washington should lean on its European allies to spend the money and place the orders to equip Ukraine. America’s commitments may falter, whether because of popular dissatisfaction, a new president, or crises elsewhere in the world. Moscow, too, may eschew talks, reasoning that Ukraine’s position is only getting weaker. To mitigate these possibilities, Washington should shift more of the burden to European countries whose proximity to Russia give them a strong interest in Ukraine’s success. These states have already begun to step up; the Czech Republic, for example, has spearheaded an innovative ammunition initiative. But Europe can do much more: increase national funding for ammunition and rocket production, authorize emergency funds and improve cross-continent defense procurement through the European Union, and take over the organizational burden of coordinating aid.

This time, Congress eventually delivered. Next time, it might not. On both sides of the Atlantic, governments should prepare for U.S. aid to dry up and work to place Ukraine on a more strategic and durable footing. After all, current levels of support have not sufficed to put the worst outcomes—whether a Russian breakthrough, a destructive forever conflict, or an expanded war—out of view. Averting those outcomes requires opening the space to weigh difficult trade-offs now. You can take only so many all-or-nothing gambles until you end up with nothing.