Paul B. Stares is General John W. Vessey senior fellow for conflict prevention and director of the Center for Preventive Action at the Council on Foreign Relations.
More From Our Experts
This Ukraine Policy Brief is part of the Council Special Initiative on Securing Ukraine’s Future and the Wachenheim Program on Peace and Security.
Executive Summary
More on:
NATO (North Atlantic Treaty Organization)
Although the prospects for an early ceasefire in Ukraine remain poor, the United States, along with its European partners, should prepare and plan for a durable peace agreement. This includes designing ceasefire provisions that would help assuage Ukrainian and European concerns about potential Russian recidivism, specifically by making it prohibitively costly in political, economic, and military terms for Moscow to violate an agreement.
Introduction
President Donald Trump’s efforts to bring a swift halt to the conflict in Ukraine have not yielded the results he promised and clearly desired. The gulf between the negotiating positions of the two sides remains wide and it is hard to imagine that ongoing U.S. efforts to broker a ceasefire (and better still, a durable peace settlement)—the latest being the August 2025 summit between President’s Trump and Putin––will prove successful any time soon. Indeed, there is every reason to expect that the war will grind on through the rest of the year and into 2026.
Given the current poor prospects for serious ceasefire negotiations, the temptation to defer planning and preparation for the day when they begin in earnest—as they surely will at some point—is very strong. This is particularly true for the technical provisions or instrumentalities of a ceasefire. Putting off such questions, however, would be shortsighted for two reasons. First, the possibility that the stars could align suddenly to make peace possible in Ukraine cannot be summarily dismissed. Being ready for that moment is vital as negotiations undertaken in haste and without due attention to practical details can lead to flawed and short-lived agreements. Second, prior understanding of how a ceasefire—if designed with forethought and care—can ease the security concerns of both parties, especially Ukraine’s, could help facilitate an agreement when the moment is ripe.
More From Our Experts
For Ukraine, one—if not the most—important concern with any ceasefire agreement is the potential for Russian recidivism that could threaten its security; indeed, Ukraine’s very survival as an independent sovereign state is at stake. More attention needs to be paid to the question of how a ceasefire agreement can enhance Ukraine’s ability to deter future Russian aggression. That question is not just vital to Ukraine’s security, but to NATO’s, too. How directly the United States will be involved in ceasefire and peace talks remains to be seen, but it has a major interest in ensuring a successful outcome.
The Desired Elements of a Ceasefire
Ideally, a ceasefire in Ukraine should aim to be more than a temporary or otherwise circumscribed suspension of hostilities (usually called a truce) and instead serve as the foundation for a permanent and comprehensive settlement of the conflict—a peace treaty, in other words. The latter are often difficult to achieve in the short term, but interim arrangements that formalize and institutionalize a ceasefire agreement are possible. Those arrangements typically establish ways to reduce the likelihood of hostilities resuming while also addressing other needs such as expediting the repatriation of combatant remains and prisoner exchanges and facilitating the movement of civilians, particularly divided families, in affected areas. To be sustainable, such arrangements usually require a clear and mutually accepted demarcation of those areas where opposing forces can be present (i.e., lines of control, or LoC) and where they cannot (i.e., demilitarized buffer zones). Mechanisms to monitor compliance and resolve any disputes are also desirable.
More on:
NATO (North Atlantic Treaty Organization)
For Ukraine, the most important concern in any ceasefire negotiation (besides the legal status of areas still under Russian control and the well-being of its citizens within them) will be whether Russia could use the respite provided by a ceasefire to rest and refit its military forces to resume offensive operations at a later date with more decisive results. Such fears are all the more warranted by Russia’s insistence that Ukraine become a demilitarized, neutral state—in effect, foreswear ever becoming a member of NATO or any other security organization considered hostile to Russia and accept significant limits on its own national defense capabilities and the presence of foreign forces in its territory. Understandably, such terms are deal breakers for Ukraine.
Bridging the gulf between those seemingly irreconcilable negotiating positions will not be easy, but the parameters of a mutually acceptable ceasefire have been proposed by several experts. In effect, Ukraine would accept de facto (but not de jure) Russian control of territories it currently occupies and abjure future membership of NATO. For its part, Russia would accept Ukraine’s right to self-defense and ideally the presence of international ceasefire monitors, if not a reassurance force, as suggested by some European members of NATO.
Such terms would leave Ukraine exposed to the risk of renewed aggression by Russia and largely without external security guarantees to deter future attacks. Several studies have argued that with continued Western financial and military assistance Ukraine has the necessary manpower and materiel to ensure its survival, as it has largely done to date. Even so, the challenge for Ukraine will remain formidable given its underlying power disparity with Russia. It is for this reason that the provisions of a ceasefire or peace agreement become especially important for Ukraine and, by extension, NATO.
Deterring Renewed Aggression
Any prospective ceasefire or peace agreement should aim to make the cost of Russian recidivism prohibitively high. No single provision in an agreement is likely to accomplish this goal, but a combination of measures could make Moscow think twice about violating an agreement.
Political Costs: Although Russia has shown scant regard for international public opinion since the beginning of its full-scale invasion of Ukraine, it cannot afford to become so isolated politically such that it jeopardizes the vital economic support it receives from China and India, among others. For this reason, Ukraine and its supporters should maximize the diplomatic investment of the international community—especially China and India—in the durability of a ceasefire agreement. Inviting both powers, as well as others from the Global South, to become diplomatic “guarantors,” if not active participants, in the implementation of a ceasefire or peace agreement—something that they could welcome––is one way to raise the bar for Russia and nudge them toward an agreement. Some combination of economic “carrots and sticks,” which the Trump administration has wielded with friends and foes alike, could be required to accomplish this goal. Having the other members of the UN Security Council endorse a ceasefire or peace agreement would also increase the political cost of violating it for Russia—more so if an international monitoring force is also established with personnel from UN member states. Economic Costs: Russia will likely make its acceptance of a ceasefire or peace agreement with Ukraine conditional on the lifting of the economic and financial sanctions that have been imposed on it since 2022 and earlier. Supporters of Ukraine will be reluctant to agree to any such relief and would insist that it be conditional on sustained observance of specific compliance benchmarks, not to mention Russian reparations. Regardless of what is eventually negotiated, any agreement should contain a snap-back provision to facilitate the rapid reimposition of sanctions and other penalties in the event Russia violates its terms. This was one of the innovative features of the 2015 Joint Comprehensive Plan of Action nuclear agreement with Iran. Military Costs: Although the value of various political and economic disincentives to dissuade Russia from violating a ceasefire or peace agreement should not be dismissed, the most important factor in Russia’s calculus will be whether it believes it can someday resume offensive operations with a reasonable prospect of achieving its operational goals at an acceptable cost. This calculation will hinge primarily on whether Russia believes it can amass a significant amount of offensive military power on its side of the line of control so that it can attack, overwhelm, and break through Ukraine’s defenses. Ideally, therefore, a ceasefire or peace agreement should aim to inhibit Russia’s offensive potential and enhance Ukraine’s defensive prospects.
The former can be achieved in several ways. The first is by restricting the ability of either side to mass forces in a deceptive or otherwise difficult-to-detect fashion. This can include setting limits on the size and frequency of military exercises within a certain distance of the LoC to prevent their potential for offensive action—a feature of the earlier confidence-building agreements in Europe. At the same time, restrictions can be placed on the deployment and movement of certain types of weapons within specified distance of the LoC. This was a feature of the earlier Minsk Accords between Russia and Ukraine. Moreover, various monitoring and inspection regimes can also be negotiated to enhance national technical means of verifying compliance. For example, allowing overflight of areas of a specified depth on each side of the LoC, granting the right to inspect suspicious activities at short notice, and placing passive sensors capable of detecting the movement of troops and materiel at agreed transportation hubs are all practices that have been used in past ceasefire agreements. Those activities could be left to Russia and Ukraine to implement or be the responsibility of an international monitoring force.
The latter—enhancing defensive operations—can be achieved in a ceasefire agreement by not restricting activities that would complicate offensive actions. This includes, most importantly, the construction of various fortifications and barriers as well as the placement of minefields, the value of which has been proven for both sides on numerous occasions during the war. Given the length of a prospective LoC, which will likely exceed any prior ceasefire agreement, it is important that Ukraine’s freedom of action not be limited.
Such measures are mainly focused on land operations, but a comparable approach should be adopted where possible to the maritime, air, and cyber domains.
Although these provisions primarily address Ukraine’s security predicament, Russia will likely demand reciprocal protections. In effect, the same provisions would also need to constrain Ukraine’s ability to violate a ceasefire (with or without foreign assistance) in ways that would challenge Russia’s control of the occupied territories. The precedents set in any such ceasefire agreement in Ukraine could also have wider benefits if they are later adapted to help stabilize the even longer NATO-Russia border.
Recommendations and Conclusion
The United States and Ukraine’s other partners should provide Ukraine with their fullest support possible when negotiations to cease hostilities and, better still, find a durable end to the war eventually commence. This backing will require clever and creative diplomacy to ensure that Ukraine’s future is secured. The prospects for such negotiations are currently unpromising, but it is not too early to plan for them and, in particular, consider how the provisions of an agreement should maximize Ukraine’s long-term security. Accordingly, under the direction of the current national security advisor or secretary of state, an interagency working group should be established to study and recommend ways to support that goal.
At the same time, a complementary NATO working group should be set up with the same objective. As with other ongoing liaison mechanisms, representatives from Ukraine should be invited to participate in its deliberations. Although the working group’s focus will be on helping Ukraine prepare for and manage future ceasefire negotiations, it should also be mindful of how creating a stable LoC in Ukraine could set useful precedents for managing NATO’s lengthy border with Russia in ways that lessen the risk of conflict.
This work represents the views and opinions solely of the author. The Council on Foreign Relations is an independent, nonpartisan membership organization, think tank, and publisher, and takes no institutional positions on matters of policy.