By:  Lawrence J. Korb, and Stephen Cimbala

The greatest challenge will be ensuring that Russia does not renew its appetite for swallowing the remainder of Ukraine at the first opportunity.

Donald Trump as a presidential candidate in 2024 and now president in 2025 indicated his intention to obtain a peace agreement that would end the three-year war between Russia and Ukraine by engaging in direct talks with Russian president Vladimir Putin. Russia’s invasion of Ukraine, which began in February 2022, has cost many Ukrainian and Russian lives and left much of Ukrainian infrastructure devastated. 

Ukrainian president Volodymyr Zelensky, for his part, demanded that he be included in any peace talks. The major European countries have indicated a willingness to contribute to post-settlement peacekeeping forces deployed in Ukraine, they have also demanded that they be part of any negotiations.

Although the case for a peace agreement in Ukraine is compelling from a humanitarian standpoint, and even if Ukraine and our European allies become part of the negotations finding the correct protocols to accomplish this mission in a way that satisfies all parties, particularly the Russians, poses major obstacles for participants in negotiations and their various supporters and interlocutors. The objectives and structure for such negotiations must include:

1) Arranging a cease-fire in place at a time agreed upon by Ukraine and Russia;

2) Stipulating which forces on each side can remain stationed on Ukrainian territory after the ceasefire and during follow-on negotiations. For this purpose, Crimea will be assumed as Russian territory, but the status of other oblasts and towns in the east and south of Ukraine will be subjects for further discussion.

3) During the negotiations, neither side should be permitted to engage in short or long range attacks by ground, maritime or air forces against the forces of the other side, nor against populations located within their respective spheres of influence; this restriction includes clandestine operations making use of proxies or other unconventional warfare or covert action.

4) States or groups of states represented at the talks should include, in addition to Ukraine and Russia: the United States; the European Union; the UN Security Council; and the Organization for Security and Cooperation in Europe (OSCE). Observers representing other interested states and organizations can be invited, including from NATO and the European Union.

The long-range objectives for negotiators will have to include the establishment of a timetable for the withdrawal of all foreign combatant forces from Ukraine, with the exception of Russian forces located on former parts of Ukraine claimed by Russia, and subsequently accepted as Russian by Ukraine and its supporters in the United States and NATO.

In addition, a monitoring and verification system will have to be established by a treaty agreement, and a multinational force will be created for deployment along the line of control between Russian and Ukrainian territory and elsewhere within Ukraine as needed. A peacekeeping force of 50,000 to 100,000 ground troops supported by other arms of service and intelligence organs is ideal. Still, under exigent circumstances, a slightly smaller force could fulfill the mission efficiently. 

The credibility of a peacekeeping force depends not so much on its size but on the tasking and cooperation of the various state parties in the agreement. The peacekeeping force is not a combatant force, but a force to observe and report on the status of events as they unfold. The peacekeeping force should have clear rules of engagement and the right to self-defense if attacked. Negotiating parties will determine what states can contribute to the peacekeeping force. The force should preferably be under the aegis of the UN Security Council regardless of its membership in order to legitimize its status within the international community. Neither NATO states nor Russia should have troops assigned to this force, although Ukrainian and Russian observers should be permitted in the demilitarized zone separating the two sides.

The endgame of negotiations should be to move from the temporary and expedient line of control and demilitarized zone immediately following an armistice to a more permanent and durable demarcation of what is Russian and what is Ukrainian. This will have to be spelled out in detail and agreed by all participants before further steps are taken, including the removal of Ukrainian and Russian military forces to their respective post-agreement zones. The challenge thereafter will be to turn the restructured zonal regions into politically cohesive and military defensible entities, especially on the Ukrainian side. 

The larger challenge will be to ensure that Russia does not renege and renew its appetite for swallowing the remainder of Ukraine at the first opportunity. This objective requires that the United States, the European Union, and NATO’s support of free Ukraine with military assistance for the sake of deterrence, economic aid for the rebuilding of its devastated economy, and above all, security guarantees against a Russian repeat of 2022. 

The security guarantees should provide that the guarantor parties affirm their commitment to a sovereign, independent and democratic Ukraine and its post-agreement borders, and that further aggression will require prompt diplomatic and military steps by the United States, NATO and the EU, in order to return the situation to the status quo ante. In the case of a major military attack by Russia against Ukraine, a la 2022, the United States and NATO will respond immediately from a menu of political, economic, and military options. 

The military options should be developed during post-peace agreement training of NATO European and U.S. military forces in scenarios ranging from limited war to full engagement between NATO and Russia. Russia should be left in no doubt that further aggression against Ukraine will be met with appropriate military force, diplomatic suasion and economic coercion. Russia should expect that it will face a range of responses that assure its international political isolation and military defeat.

While these negotiations could end the current crisis, to bring about “strategic” war termination in Europe means not only blunting Putin’s aggression against Ukraine, but deterring more broadly his military adventurism and political coercion of free Europe for the remainder of his tenure in office. Temporarily stalemated in Ukraine, Putin is likely to move on to other targets of opportunity. The Baltics are especially cognizant of this and have led the way in NATO preparations for downstream Russian revanchism. Nordic countries, among others, have increased their preparedness for civil defense and other aspects of planning for a prolonged war against Russia if it comes to that. 

Russian aggression against a NATO member state raises the stakes considerably beyond its risk-acceptant attempt to exert regime change in Ukraine. NATO includes three member states that also have long-range nuclear forces (the United States, UK, and France), and each of the nuclear forces includes ballistic missile submarines that are not vulnerable to a first strike. Russia does have many more non-strategic or tactical nuclear weapons than NATO, and some fear that this creates a deterrence gap between Russia and NATO below the level of long-range nuclear forces. However, the threat of nuclear first use by Russia was repeatedly brandished by Putin during the war in Ukraine and had little apparent effect on NATO resolve to stay the course. 

The future of U.S., NATO, and EU relations with Russia is more open-ended than current events might suggest. Putin doubtless holds absolute power in Russia and a post-Putin world is not imminent. However, more pragmatism in Russian decision-making with respect to war and peace should not be ruled out as the decade progresses. Putin and his advisors must recognize that their expectations about Russia’s ability to execute modern combined arms warfare against Ukraine (and potentially NATO) have been seriously undermined. Modern warfare involves more than the mastery of mass infantry attacks, long range artillery fires, and tactical airpower equipped with glide bombs or other strike weapons. New technologies including drones, advanced suites of C3ISR(command, control, communications, intelligence, surveillance and reconnaissance), and cyberwar have created a leitmotif of information-based battlespace that takes war beyond the symphony of heavy metal clashes.

In addition to a need to reboot its tactical and operational learning curves, Russia also needs to rethink its diplomatic-strategic behavior. One outcome of Russia’s war against Ukraine was to enlarge NATO to a membership of thirty-two countries, including previously neutral Sweden and Finland. And, although Putin and Chinese leader Xi Jinping have entered into an alliance of sorts on some issues of military preparedness and foreign policy, China’s support for Russian aggression in Europe is conditional with respect to how extensive and how dangerous Russian ambitions prove to be. 

China has extensive economic interests in Europe and, other things being equal, would prefer a user-friendly climate for investment and economic stability to a war-torn prospectus of economic uncertainty. Finally, China has indicated quite clearly its opposition to any nuclear first use by Russia in the current war against Ukraine, and China’s view of the postwar peace agreement will be an important marker of its potential durability in the broader international system beyond Europe.

Stephen Cimbala is a Distinguished Professor of Political Science at Penn State Brandywine and the author of numerous books and articles on international security issues.

Lawrence Korb, a retired Navy captain, has held national security positions at several think tanks and served in the Pentagon in the Reagan administration.          

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