Donald Trump has held separate calls with Vladimir Putin and Volodymyr Zelenskyy ahead of the NATO summit in Ankara, again presenting the United States as the central mediator capable of bringing the Ukraine war towards an end. Zelenskyy described his conversation with Trump as productive and said there was a “real prospect” of ending the war, while the Kremlin characterised Trump’s lengthy call with Putin as constructive. Yet Russian forces continue offensive operations in eastern Ukraine, and Moscow and Kyiv remain divided over territory, security guarantees and the political status of occupied regions. After more than four years of full-scale war, the most interesting question is no longer whether negotiation is necessary; almost every war eventually requires it. The harder question is what justice can realistically mean when negotiations occur after force has already changed the facts on the ground.
This is where the tension between realism and liberal internationalism becomes unavoidable. Realism tells us that Russia’s control of territory matters because political settlements cannot simply pretend military power does not exist. Ukraine may possess the stronger legal claim while still lacking the military capacity to restore every internationally recognised border at an acceptable cost. Liberal internationalism, however, exists partly to resist the conclusion that whatever a powerful state can conquer eventually becomes legitimately its own. If military occupation automatically converts into recognised sovereignty after enough time passes, international law stops constraining conquest and begins merely recording its results. A peace settlement therefore has to acknowledge battlefield reality without turning battlefield success into a general legal principle.
This is why the distinction between de facto control and de jure sovereignty remains so useful. Ukraine could accept that it will not attempt immediately to recover some Russian-occupied territories through military force while refusing formally to recognise those territories as Russian. The ceasefire line would determine practical control without necessarily determining permanent ownership. This is intellectually untidy, but international politics frequently survives through deliberate ambiguity. Not every dispute needs to be solved immediately if attempting to solve it makes agreement impossible. Sometimes peace requires deciding which questions can remain unanswered safely.
The stronger objection is that such a settlement might reward aggression anyway. Russia would still possess territory it did not control before invading. That concern is legitimate because international rules operate partly through incentives. If future governments conclude that invading a neighbour can produce territorial gains after enough military persistence, the expected return to aggression increases. The settlement therefore needs other costs strong enough that Russia cannot reasonably interpret the war as profitable overall: continued non-recognition of annexation, some sanctions, Ukrainian integration with Europe and, most importantly, a much stronger Ukrainian defence capability. Deterrence does not require reversing every gain an aggressor obtained; it requires ensuring that the total expected return from repeating the strategy becomes negative.
Ukraine’s security guarantee is consequently more important than the symbolism of the eventual map. A ceasefire without credible deterrence could simply provide Russia time to rebuild forces. Kyiv’s scepticism is rational because the Budapest Memorandum and later diplomatic arrangements failed to prevent Russian aggression. A future guarantee therefore needs operational meaning. Which weapons are automatically supplied if Russia attacks again? What intelligence support begins? What sanctions return? What role do European forces play? The credibility of the guarantee depends less on elegant treaty language than on whether Moscow believes those consequences will actually occur.
Europe increasingly understands that it cannot outsource this responsibility completely to Washington. European states will live with the settlement geographically, finance much of Ukraine’s reconstruction and probably provide a substantial part of any long-term military guarantee. This creates a basic principle of political legitimacy: those expected to bear the consequences of an agreement should possess meaningful influence over its design. American mediation remains enormously valuable because Washington possesses leverage neither Europe nor Ukraine has independently, but leverage should facilitate negotiation rather than substitute for the agency of the states whose future is being negotiated.
Trump’s approach is interesting because it is much more explicitly transactional than the language usually surrounding international law. He appears to view peace largely as a bargain in which each actor must accept that it cannot obtain everything it wants. There is considerable truth in this. Political compromise requires recognising constraints. Yet transactional diplomacy becomes dangerous when it treats all claims as simply divisible interests. Territory is inhabited by people. Security guarantees affect whether families return home. Sovereignty represents a population’s claim to political self-government. Not every political good can be divided as though negotiators were distributing shares in a company.
Putin’s argument, meanwhile, continues to invoke Russia’s security concerns about NATO enlargement and Ukraine’s Western alignment. Those concerns should be understood seriously without granting them unlimited normative authority. Great powers genuinely care about military alignments near their borders. America demonstrated the same instinct during the Cuban Missile Crisis and continues to care intensely about strategic developments in the Western Hemisphere. But recognising that security concerns exist is different from accepting a sphere of influence in which neighbouring countries lose the right to choose their own relationships. If Russia’s insecurity automatically overrides Ukrainian sovereignty, then small states become independent only where great powers permit them to be.
This is the fundamental philosophical problem with spheres of influence. They can produce stability because great powers receive buffers and clearer boundaries. They can also produce stability by denying smaller societies political agency. The fact that an arrangement reduces conflict between great powers does not automatically make it just for the countries living between them. A durable European order therefore needs to accommodate Russian security without converting Ukraine into a permanently subordinate state.
Ukraine itself also has to think beyond the immediate territorial dispute. Millions of citizens remain abroad, infrastructure requires enormous reconstruction and the demographic cost of continued war increases every year. The value of sovereignty ultimately lies partly in what the sovereign state enables its citizens to do. A Ukraine controlling every possible kilometre but losing another generation to war could emerge territorially larger yet socially weaker. Conversely, a somewhat smaller but secure Ukraine integrated into European markets could become wealthier, more democratic and more capable over time. This does not mean territory is unimportant. It means territorial maximalism can conflict with the human purposes for which territory is politically valuable in the first place.
That is why the opportunity cost of continued war needs to be discussed without implying Ukraine should simply surrender. The correct comparison is not an imperfect peace against an ideal restoration of the 1991 borders achieved without further casualties. It is an imperfect peace against the expected outcome after another year or two of fighting. If continued resistance substantially improves Ukraine’s future bargaining position, it can be rational. If thousands more deaths merely move the eventual line marginally, refusing compromise becomes harder to justify. Those calculations are morally painful because they translate territory and national dignity into lives, but governments already make them whenever they decide whether to continue wars.
Russia should confront the same calculation. Even if Moscow retains territory, it has paid an extraordinary price in casualties, sanctions, military expenditure, dependence on China and the expansion of NATO through Finland and Sweden. The war therefore demonstrates why territorial acquisition is a poor measure of strategic success. A state can gain land while making its wider security environment worse. Power should be judged by whether a policy increases the range of favourable choices available afterwards, not simply whether the state possesses more territory than before.
The coming NATO summit may therefore matter because it can help define the post-war balance before the war actually ends. If Europe demonstrates that Ukraine will remain heavily armed and economically integrated with the West regardless of the final territorial arrangement, Moscow’s incentive to continue fighting for marginal gains decreases. If Russia believes Western commitment will collapse eventually, waiting becomes more attractive. Diplomacy works when it changes those expectations.
Trump’s renewed mediation should be welcomed insofar as it narrows the distance between positions, but no summit or phone call can remove the underlying conflict between power and principle. Russia possesses enough military power that its preferences cannot simply be ignored. Ukraine possesses enough sovereignty that its future cannot legitimately be decided entirely by Russia and America. Europe possesses enough economic weight that it cannot remain merely an observer. The eventual settlement will therefore be imperfect because international politics rarely allows justice, security and power to align completely.
The goal should not be a peace in which everyone can claim that history vindicated them. It should be a peace that changes incentives sufficiently that Russia no longer sees invasion as an efficient instrument of policy, Ukraine no longer sees permanent mobilisation as necessary for survival, and Europe no longer depends on another war to rediscover the importance of its own defence. If Trump’s diplomacy can help produce that equilibrium, the value of the settlement will not lie in who appears to have won the negotiation. It will lie in whether the next generation of Russians and Ukrainians has less reason to fight over the same questions again.
