By Paul Robinson, Canadian Dimension, 2/13/25

In December 1990, Serbian rebels declared independence in the Croatian region of Krajina. A year and a half of war followed, ending in a ceasefire in May 1992 that left Krajina under Serbian control. The Croats, however, refused to recognize the loss of the territory, rearmed, and in August 1995 attacked Krajina and rapidly reconquered it.

In a similar vein, in May 1994, a ceasefire brought an end to the First Karabakh War between Armenia and Azerbaijan, leaving the contested province of Nagorno-Karabakh and a large amount of surrounding Azeri territory under Armenian control. But the ceasefire did not resolve any of the underlying issues that caused the war. While Armenia enjoyed the spoils of its victory, Azerbaijan rebuilt its army and in September 2020 launched the Second Karabakh War, the result of which was a decisive Azeri victory and the restoration of Azeri control of its lost territories.

And in a more recent example, after the Syrian National Army had driven anti-Assad rebels into a small corner of Syria around the town of Idlib, a ceasefire was agreed that left the Idlib area under rebel control. In the years that followed, the rebels built up their forces with Turkish help while the Assad government sat back and did relatively little. This year the rebels struck, speedily crushed the Syrian National Army and drove Bashar al-Assad from power.

These examples demonstrate that ceasefires that fail to settle the political differences underlying a war often prove to be temporary. Often the side that came out worse in the original war takes the opportunity to revive its military and then, when the time is right, renews the war in an effort to retake what it has lost.

Knowledge of this possibility can persuade political leaders not to make peace even when it would make sense otherwise to do so. In studies of war termination, this is known as the “credible commitment problem”—warring parties will not make peace as they do not believe that the commitments others make in peace negotiations are credible. Overcoming this problem is one of the most important tasks of would-be peacemakers.

As the war in Ukraine reaches the end of its third year, the credible commitment problem provides a useful lens through which to determine the prospects of US President Donald Trump’s efforts to bring the conflict to an end. These efforts have now moved firmly beyond talk into the realm of action. This Wednesday Trump announced that he had spoken to Russian President Vladimir Putin by phone and that the two had agreed to commence peace negotiations “immediately.”

The timing is propitious as the military situation provides incentives to both sides to cease fighting. This is particularly true of Ukraine whose army steadily gave ground during 2024 and whose efforts to mobilize its population have fallen flat. Despite draconian conscription methods, recruitment to the army is insufficient to replace losses and desertion is increasingly common. A continuation of the war almost certainly means further losses of land, people, and infrastructure with no gains in return. Ukraine’s best option at this point is to cut its losses and make peace.

This does not mean, however, that Russia is close to what it might consider victory. The pace of its advance is painfully slow and there are currently no indications that the Russian army is capable of a major breakthrough. Given its superior resources, the attritional process favours Russia and may lead eventually to Ukraine’s “debellation.” But we do not as yet appear to be anywhere close to that. At least for the coming year, Russia faces the prospect of costly war for relatively few gains. It too would benefit from peace.

In theory, therefore, this is a good time for Trump to step forward with his peace plan. Press reports suggest that the first step would be a ceasefire, followed by a Ukrainian withdrawal from the land it holds in Russia’s Kursk province, and the introduction of a European peacekeeping force. Ukraine would be prohibited from joining NATO and would recognize Russian sovereignty over captured territories, but would continue to receive military support from the Western states and would be promised an accelerated process towards membership of the European Union.

Further clues about American thinking came on Wednesday with a speech in Brussels by the new US Secretary of Defense Pete Hegseth. In this Hegseth declared that “we must start by recognizing that returning to Ukraine’s pre-2014 borders is an unrealistic objective.” Hegseth added that “the United States does not believe that NATO membership for Ukraine is a realistic outcome of a negotiated settlement,” and that “any security guarantee must be backed by capable European and non-European troops. If these troops are deployed as peacekeepers to Ukraine at any point, they should be deployed as part of a non-NATO mission. … There will not be US troops deployed to Ukraine.”

Importantly, Hegseth showed himself to be aware of the credible commitment problem, noting that “A durable peace for Ukraine must include robust security guarantees to ensure that the war will not begin again.” The question then arises of whether his government’s plan can convince the two warring parties that this is indeed the case.

This is by no means certain due to the fact that neither side trusts the other to stand by its commitments. Ukrainian President Volodymyr Zelensky, for instance, has repeatedly expressed his fears that Russia will exploit any pause in the fighting to its own advantage, declaring that “A pause on the Ukrainian battlefield will not mean a pause in the war. A pause would play into [Russia’s] hands. It might crush us afterward.”

This is why the issue of security guarantees has acquired such salience. Zelensky is unlikely to make peace if he believes that the war will later resume in circumstances that are even less favourable than today. But he could perhaps be persuaded if outside powers provide guarantees that the Russians will be forced to obey the peace treaty’s terms. For Zelensky, the most solid guarantee is NATO membership. Hegseth’s rejection of this is therefore a serious blow to the Ukrainians’ ability to trust in the permanence of any ceasefire. It is not clear whether the possibility of some non-NATO peacekeeping force will be a sufficient guarantee to overcome this problem. The US government needs to be ready to do some serious diplomatic arm twisting to get Kyiv to acquiesce.

As for the Russians, their experiences with the Ukrainians have also left them with reasons to doubt whether any peace will be permanent. In August 2014, the Ukrainian army suffered a serious defeat at the battle of Ilovaisk in Donetsk province. Had Russian-backed rebel forces continued their advance, it is possible that Ukraine would not have been able to offer serious resistance. Instead, the Russians agreed to a ceasefire under the terms of an agreement signed in Minsk.

The ceasefire, however, failed to hold. Fighting continued, eventually resulting in another Ukrainian defeat in early 2015. Again, Russian president Vladimir Putin refused to exploit his advantage and agreed to another ceasefire, this time according to the terms of the Minsk II agreement. But this ceasefire also failed to hold. Meanwhile, the Russians accused the Ukrainians of not fulfilling the political terms of the Minsk agreement, above all granting autonomy to the provinces of Donetsk and Luhansk. At the same time, the Ukrainians rebuilt their broken army, aided by Western weapons and trainers. The final conclusion drawn by the Russians was that the ceasefire was a mistake and that the Ukrainians could not be trusted to abide by another.

Due to this, there is an extreme reluctance on the Russian side to agree to peace proposals that do not ensure that Ukraine abides by its commitments. Trump’s peace plan does address this problem to some degree, first by ruling out NATO membership for Ukraine and second by requiring that Ukraine formally recognize Russian sovereignty over its captured territories. This last point is particularly important, as if the war ends in such a way as to leave a territorial dispute between Russia and Ukraine, the possibility that it will eventually resume is much greater. The prospect of Western weapons continuing to flow into Ukraine and of European troops being deployed there may well disconcert Moscow and discourage it from accepting what is on offer, but the offer is still one that gives it considerable gains. If it is wise, it should not dismiss the offer out of hand.

One of the difficulties here is that anything that reassures Ukraine that the Russians will not break the terms of any peace treaty (for example, promises of future weapons supplies) almost certainly has the opposite effect on the Russians, increasing their fears that Ukraine might eventually renew the war. The Trump peace plan goes some way towards squaring this particular circle by providing some guarantees to both sides, albeit far fewer than both would like. As such it is a reasonable compromise and a good starting point for further talks. There will be some hard diplomatic work ahead, but at least the long process of negotiation is finally about to start.

Paul Robinson is a professor in the Graduate School of Public and International Affairs at the University of Ottawa and a Senior Fellow at the Institute for Peace and Diplomacy. He is the author of numerous works on Russian and Soviet history, including Russian Conservatism, published by Northern Illinois University Press in 2019.