Since the early days of Russia’s war against Ukraine, some have called for the Ukrainians to sue for peace. The initial verdict of these commentators was that Russia’s military superiority made fighting virtually a lost cause. When Ukrainian fighters exceeded expectations, it was suggested that Ukraine’s supporters and suppliers broker a negotiated end to the war. Ukraine had made its point by standing up to Russia, but little more could be accomplished by prolonging the conflict. As the war continued, so did these assessments, predicting that European support for Ukraine would flag as rising energy prices squeezed consumers, bringing Ukraine’s valiant run to an end like France’s defeat of Morocco in the 2022 World Cup Semis.
These kinds of arguments appear strong in their appeals to prudence, yet retain the signal disadvantage of being wrong. An alternate version of these arguments is that the risks of Ukraine actually defeating Russia are too great for Ukraine to keep fighting because a desperate Putin is a dangerous Putin. Faced with a real possibility of defeat by conventional means, Russia might launch a nuclear weapon, or take some other offensive measure that would compel a wider military response, and that would trigger World War III.
Together, these form a heads-I-win, tails-you-lose argument. On the one hand, Ukraine shouldn’t fight because it cannot win. On the other hand, Ukraine should not fight because it can win. So which is it?
The weaknesses in these arguments are not just logical or factual, they are moral. The first error is a mistaken attribution of moral responsibility: Russia, not Ukraine, is morally responsible for the war and all of the destruction that flows from it. Putin made the choice to attack Ukraine in the absence of a credible threat, committing an act of unjust and illegal aggression. Ukraine bears no responsibility to shorten the conflict to its own disadvantage. The moral rightness of Ukraine’s cause is not a minor point: it is the whole argument.
Similarly, Russia’s actions have caused suffering and hardship not just in Ukraine, but around the world. While the actions of other nations can help alleviate or even contain the suffering, they are not the true cause of it. The risks to the global order flow not from Ukraine’s response to Russia, but from Russia itself.
Soi-disant realists apparently conclude that the strategic aim of war is to limit losses, rather than to win the conflict. Perhaps reflecting a post-Vietnam lowering of horizons, their perspective seems like a version of the view that while war may be morally just in theory, it is rarely (if ever) so in practice. Even if the right side should win in theory, the cost of winning in practice is just too high.
Neglected in this calculation is the cost of losing. Standing down because of the risk of a nuclear strike means entering into the nuclear blackmail phase of international relations. In this stage, the possession of a nuclear weapon is sufficient not only to guarantee the security of a regime but also to license its aggression. To my mind, this outcome is at least as likely as the alternative.
Those who would have Ukraine negotiate with Russia assume that by doing so, the costs of conflict could be avoided, rather than paid in a different currency—through ongoing crimes of the Russian regime, the lack of freedom and self-determination for the Ukrainians living under Russian rule, and the strengthening of authoritarianism and weakening of liberal democracy across the globe.
Just war thinking offers an alternative to a mere calculation of costs and benefits or national interest. Though clear about the moral stakes of armed conflict, just war thought focuses so much on jus ad bellum and jus in bello that it sometimes backgrounds the most basic tenet: the goal of fighting a war is to win the war, to vindicate the cause of justice against unjust aggression, and to pave the way for a more durable peace.
Acknowledging that war is likely a permanent feature of the human condition, just war principles offer tools for thinking about how to contain—not eliminate—the destructive effects of war. Precisely because the costs are high, these principles limit just causes for war. But these tools were not intended to suggest that once a conflict has begun, prudence should dictate negotiating its end before the outcome is clear.
Still, there are things that we can learn from the quasi-realist perspective, flawed though it is. One is our tendency to evaluate wars in hindsight: when our side wins (or is winning), we are more apt to see the cause as just. When our side loses (or is losing), we are more likely to see the war as unjust. We should guard against this tendency. Though we should rejoice when a just cause is vindicated by victory, winning is not indicative of moral superiority, nor is losing a failsafe sign that a cause was unjust.
The progress of the war in Ukraine reminds us that wars are unpredictable. Voices proclaiming victory can be wrong as much as voices portending defeat. That is why jus ad bellum makes prudential concerns secondary: when we cannot know the outcome, we cannot use it to determine the right course of action. The utilitarian calculus is only reliable after we know the final result.
I do not know, finally, what will happen in Ukraine. But I know what should. Ukraine should win, and we should continue to do whatever we can to help them achieve that goal.