A N A LYS I S Fred Tanner(June 2026) The OSCE in a post-war scenario in Ukraine The OSCE – a central paradox A ceasefire in Ukraine seems far away at the moment. Nonetheless, the Ukrainian president has urged the international community to try to end this war. Therefore the question will arise, how such a ceasefire could be implemented and which organisation will take on which task. Many eyes will turn to the OSCE for that matter. This paper examines the role the OSCE could realistically play in a post-war scenario in Ukraine, and under what political and operational conditions. The question has become urgent: the Swiss Chair-in-Office has asked the OSCE to step up preparations to ensure it is fit to take on a targeted, credible and complementary role in the event of a de-escalation or ceasefire between Ukraine and Russia. More specifically, the paper explores the relationship between a potential settlement and the future relevance of the OSCE as a»soft« security actor. The question is not simply what the organisation is capable of in theory, but what functions it could credibly perform in a highly contested post-war environment, alongside such actors as the EU, the UN and NATO. While the OSCE possesses the broadest ranging civil-military toolkit among Europe’s security organisations, its power of enforcement is the weakest. Its added value is not so much hard power as legitimacy, normative anchoring and operational depth. This encompasses 30 years of field mis sions from Skopje to Dushanbe, each a lesson in what can happen when mandates collide with political reality. A settlement of the war against Ukraine raises one structural question immediately: how much operational space would remain for the OSCE, and on whose terms? The issue is not confined to whether it can play a role, but also extends to what role, under what conditions and where others must take the lead. Institutional memory is not a substitute for political will. Operational continuity is not a mandate. That design choice will not be made in Vienna. It will be made in Washington, Kyiv, Moscow and Brussels. And the OSCE will inherit whatever space remains after the negotiations conclude. The realistic entry points are modular, subsidiary and technically grounded. The field record is consistent: narrowly defined, status-neutral mandates have endured. Overreach – or loss of host-state consent – ended them. The OSCE in a post-war scenario in Ukraine 1

1. Division of labour and strategic complementarity The OSCE does not operate in a vacuum, but as a critical node within a broader, multidimensional international response framework. Its core strategic advantage lies in its capacity to fill operational voids where other actors are constrained by rigid mandates or polarised political configurations. Residual multilateralism as a comparative advantage While the OSCE is rarely the first choice of institution, it frequently emerges as the last viable option. It is uniquely positioned to act in environments in which NATO or the EU are perceived as a direct parties to the conflict, the EU might be restricted by its exclusive accession logic, and the UN Security Council is paralysed by vetoes. This is not a structural defect, but rather a distinct niche. The OSCE remains the sole inclusive platform capable of operationally implementing technical security measures while simultaneously keeping Russia, Ukraine and the United States on board. Russia, as a participating State, holds a veto over consensus-dependent mandates – yet the Extra Budgeting (ExB) financing model and technically-framed Special Programme Ukraine(SPU) activities demonstrate that operational space exists even without Moscow’s active consent. The OSCE and the EU— institutional synergies The Balkans offers the most instructive precedent. Where the EU provided the political and economic architecture of post-conflict stabilisation – through conditionality-driven reform and the prospect of accession – the OSCE supplied the operational and normative layer: election monitoring, institution-building, arms control and field presence in territories in which EU leverage did not yet reach. The model worked not because any single actor was sufficient, but because each occupied a clearly delimited lane with complementary incentive structures. For Ukraine, the same division-of-labour logic applies. The EU drives long-term structural transformation through reconstruction and the accession process, while the OSCE operationalises stabilisation – ceasefire monitoring, confidence and transparency building, verification and minority protection – extending its reach to regions and populations where Brussels carries too much political weight to be perceived as neutral. The OSCE can therefore go where the EU cannot, without foreclosing its own leverage. The OSCE and the UN Framework An explicit mandate under Chapter VIII of the UN Charter is a non-negotiable structural prerequisite for any OSCE verification task that extends beyond baseline capacity-building. The OSCE’s Special Monitoring Mission to Ukraine’s(SMM) core failure was precisely this: physical presence without empowerment, monitoring without enforcement. The lesson from three decades of field missions is unambiguous in this respect: civilian monitoring bodies that lack a credible escalation ladder do not deter violations, they just document them. Documentation without consequence eventually becomes irrelevant. 2. What the OSCE can deliver in a post-war setting in Ukraine The following typology draws directly on concrete field mission experience and is structured in terms of political attainability and operational capacity. A: High level feasibility— immediate entry points These proposed functions and measures can be pursued independently of the political settlement context and they require no new mandates— only the programme developments already in the field. Crucially, their viability rests less on consensus among the 57 participating States than on operational partnerships, donor continuity and humanitarian necessity. Demining, Small Arms and Light Weapons(SALW) and conventional ammunition This sector represents the most structurally and politically insulated transition of existing field activities into a post-conflict function. The Support Programme for Ukraine (SPU) is already operational in humanitarian demining, chemical threat mitigation and environmental monitoring. OSCE experience in Tajikistan – where the Programme Office in Dushanbe supported the creation of a national Humanitarian Demining Centre and trained border officers along the 1,300 km Afghan frontier – confirms that such technical programmes can be operationalised independently of the broader political settlement, provided financing is secured. Mine contamination in Ukraine will outlast any political settlement by decades. Whatever framework emerges from negotiations, Ukraine will remain among the most heavily contaminated territories in the world, rendering it a humanitarian emergency operating on its own timeline, independent of ceasefire lines or diplomatic sequencing. This creates an operational space the SPU or its successor mission will be well-placed to fill. A demining coordination role – developed possibly in conjunction with the UN Mine Action Service(UNMAS) and the Geneva International Centre for Humanitarian Demining(GICHD) – would draw on existing field presence while remaining insulated from the organisation’s most acute structural vulnerability. The technical functions discussed below are viable precisely because they depend less on unanimous consensus among all 57 participating States than on operational partner ships, donor continuity and humanitarian necessity. Where political mandating stalls, technical coordination can advance. The OSCE in a post-war scenario in Ukraine 2

Information management and mapping : harmonising contaminated land registries for the efficient deployment of international and domestic demining units. → Technical standard-setting : adapting International Mine Action Standards(IMAS) to specific local terrain challenges. → Civilian risk education : building community-based explosive ordnance risk education(EORE) through established local networks, schools and digital platforms. → Equipment and procurement : channelling specialised equipment and training through existing trust funds and Extra-budgetary project funding mechanisms, that can operate outside consensus requirements. Border security management and combating illicit arms trafficking The OSCE’s working relationships with Ukrainian security authorities cannot be replicated quickly. Post-war border security management along a Ukrainian contact line will be operationally demanding and politically sensitive, and the proliferation of small arms and light weapons accumulated during years of high-intensity conflict will pose a long-term regional security threat that demands coordinated institutional response. The SPU provides a direct institutional transfer path for both functions, provided sustainable Extra-budgetary financing is in place. Expertise and operational experience in border security management will also be essential along the Belarus-Ukraine border— a segment that, given Minsk’s alignment with Moscow, poses particular challenges for any neutral or multilateral monitoring presence. Mediation and advisory subject-matter expertise Given that high-level political mediation remains constrained by geopolitical competition, project design should prioritise ground-level accompaniment over top-down process management. Where Track 1 channels are blocked, Track 1.5 and Track 2 dialogue formats offer the only viable pathway for sustaining contact between conflict parties and civil society actors, and the OSCE has the field infrastructure to support them. Switzerland brings particular added value here. Its mediation culture, institutional expertise and established neutrality constitute a comparative asset that extends beyond the OSCE Swiss chair itself, one that could be shared with lead states or organisations taking on facilitation roles in a post-conflict framework. The Swiss Chairpersonship’s Special Representative for Dialogue Facilitation already provides a useful process model; the question is whether that model may survive transfer of the chair and is embedded in durable institutional arrangements. Elections, the rule of law, and minority protection The OSCE Office for Democratic Institutions and Human Rights(ODIHR) election observation methodology has no institutional equivalent. The OSCE Mission in Kosovo built Kosovo’s Central Election Commission from the ground up, trained the first generation of post-war police and judges, and ran the country’s first elections in 2000. All these achievements underscore the organisational depth ODIHR and field missions can generate when mandated early and resourced adequately. For Ukraine, ODIHR electoral legal framework analyses and voter registry audits should begin well before election dates are set. Post-conflict elections in Ukraine will face intense external scrutiny, with neighbouring states potentially challenging the validity of the democratic process. Deploying an ODIHR election observation mission provides the rigorous technical assessment required to build and anchor international consensus regarding the legitimacy of electoral outcomes. The Baltic missions in Estonia and Latvia, 1993–2001, offer an equally instructive precedent for High Commissioner on National Minorities(HCNM) engagement. Both missions achieved conflict prevention through quiet facilitation of minority rights legislation, in close coordination with the HCNM. Their successful closure – coinciding with Baltic accession to NATO and the EU – demonstrates what a well-resourced, politically neutral HCNM mandate can achieve. For Ukraine, the HCNM can provide a legitimate framework in which to address minority issues, including the demands of the Russian-speaking population, provided the mandate remains strictly status-neutral. Preparations should include: → Institutional capacity building : strengthening Ukrainian institutions in judicial reform, minority rights and electoral administration. → Electoral framework support : conducting ODIHR legal framework analyses and voter registry audits prior to the scheduling of election dates. → Demographic mapping(politically) : utilising the HCNM for minority mapping, particularly along the contact line and in areas absorbing returning populations. B: Medium level feasibility – advisory and subsidiary roles These proposals require a stable ceasefire, but can operate on a discreet, demand-driven, non-binding support model. Crucially, they may bypass the 57-state consensus require ment if a distinct, specialised mandate is established. Advisory role in a joint military commission or civil-military coordination Unlike the post-2014 Joint Centre for Control and Co-ordi nation(JCCC), which – critically – lacked formalised procedures and enforcement mechanisms, any future militaryThe OSCE in a post-war scenario in Ukraine 3

-to-military or civil-military coordination body must be anchored in a structured accountability framework, with clear escalation procedures from the tactical to the political level. The JCCC’s failure was not primarily operational, but architectural. Without agreed compliance benchmarks, a neutral verification layer and political backing to penalise non-compliance, the mechanism became a forum merely for registering violations rather than resolving them. The Swiss Chairpersonship could contribute directly to that architectural design, bringing both its established neutrality and its military expertise to the construction of a framework that the JCCC conspicuously lacked. Subsidiary verification and monitoring Operating under a UN Chapter VIII mandate, a»coalition of the willing« or a US-led framework, the OSCE can deploy its civilian mission experience without assuming the primary leadership role. The organisation’s pioneering use of Unmanned Aerial Vehicles(UAV)and technological assets for frontline verification, developed through the SMM, is a directly transferable, high-value resource. C: Lower level feasibility— to be kept as an option These options depend on conditions not yet in place— full consensus, enforcement backing and mutual trust— and are best held as contingency plans, not immediate measures. Civilian monitoring and verification mission A comprehensive civilian monitoring mission is neither politically nor financially viable in the short to medium term. The evidence for that assessment is already on record. The frontline extends over 1,000 kilometres; UAV proliferation has fundamentally transformed battlefield monitoring in ways the SMM’s mandate never anticipated; and mutual trust between the parties is, for now, entirely lacking. The SMM’s experience from 2014 to 2022 is conclusive on this point. Even a well-resourced mission of 1,300 monitors – the largest field operation in OSCE history – could not independently verify compliance along a contested frontline without enforcement power and unimpeded access. It documented violations with considerable rigour, but it could not stop them. Where access was denied, the monitoring record became a political rather than an operational instrument. Full-scale civilian verification remains a long-term strategic aspiration. Treating it as an immediate operational option would replicate the SMM’s structural vulnerability at larger scale and political cost, but also risk discrediting the very instrument it seeks to revive. 3. Three-phase implementation sequence Field mission experience points consistently to the same lesson: organisations that wait for a political settlement to begin operational planning arrive too late to shape the outcome. The OSCE Mission in Kosovo was pre-positioned within weeks of UNSCR 1244 precisely because institution al planning had begun before the conflict ended. The result was a mission that could set up Kosovo’s election commission, police academy and judicial institute within months. The contrast with Bosnia, where international actors’ initial failure to coordinate delayed stabilisation, underlines the cost of institutional unpreparedness. → Immediate phase : The SPU operational portfolio extends beyond environmental monitoring into a cluster of soft security tasks with immediate post-war relevance:mine action, SALW, border security management, Internally Displaced Persons(IDP) protection and psychosocial assistance to conflict affected population-including children bearing the long-term psychological burden of war trauma. These are not peripheral functions. → Short-term phase : ODIHR electoral legal framework analysis; HCNM minority mapping; subsidiary monitoring support under a UN or coalition umbrella; environmental and chemical threat monitoring. → Medium-term phase : full governance support mission encompassing rule of law, judicial reform and constitutional jurisdiction, e.g. modelled after the Bosnia and Herzegovina mission, integrated into the EU accession framework but institutionally independent. 4. Preparation today: overcoming institutional lethargy The OSCE’s institutional predicament in 2026 is not a shortage of relevant experience, but rather of readiness to deploy that experience when a political window opens. Four years of budgetary paralysis have depleted personnel reserves, suspended operational planning and eroded the pre-financing capacity on which rapid mission deployment depends. The primary threat to the OSCE is not overambition, but institutional lethargy, the slow atrophy of an organisation that possesses the necessary tools but has lost the reflexes to use them. The cost of unreadiness The field record highlights the stakes. The OSCE Assistance Group to Chechnya demonstrated in 1996 that a small, well-positioned civilian team, operating with hoststate consent and a clear mandate, could contribute decisively to ending a war because it was present, trusted and operationally ready before the moment of ripeness arrived. The current negotiational impasse is not an argument for waiting, but for accelerated preparation. The Swiss ChairThe OSCE in a post-war scenario in Ukraine 4

manship’s central task is to ensure that when the window opens, the OSCE is well positioned to walk through it. Concretely, this entails three immediate priorities: → Develop planning scenarios, chair’s discussion papers, personnel rosters and pre-financing models now , without waiting for a political»deal« to define the parameters. → Coordinate with key partners, such as Germany and other lead states or international organisations to secure the political viability of an OSCE contribution before the moment arrives. → Push for adaptation of the Vienna Document : a transparency regime for demilitarised zones and specialised reporting requirements for drone activities along the contact line; a confidence-building bridge ahead of any comprehensive political agreement. 5. Supplementary analytical points The environmental and chemical dimension as an underestimated niche Ukraine faces a monumental environmental remediation task: contaminated soil and waterways, damaged nuclear infrastructure, and severe chemical pollution from destroyed frontline industrial facilities. The scale is already visible: Ukraine’s State Emergency Service recorded 2,316 emergency responses in 2025 alone, including 155 chemical and 28 radiological incidents. War damage to industrial sites and chemical storage creates long-term hazards that extend well beyond any ceasefire line and persist regardless of the end of the war. Given its comprehensive approach to security, the OSCE is structurally well suited to pursue environmental monitoring and hazard mapping along former conflict lines. The SPU already trains demining experts in environmental auditing, providing an institutional foundation that requires expansion rather than construction from scratch. Crucially, technical environmental standard-setting is apolitical by nature; it is one of the exceptionally rare operational functions the OSCE can perform without Russian caveats, and one where its established role as a neutral multilateral framework-setter carries genuine credibility. Structured dialogue as a post-conflict platform The Structured Dialogue initiated in 2016 could offer sub stantial added value within a post-conflict framework, provided there is a foundational consensus on the construction of a new security architecture. This entails seeking dialogue without conceding on principles, and making clear that engagement does not imply impunity. The OSCE’s inclusivity remains its most distinctive asset: all affected states retain a voice, including those outside NATO and EU accession dynamics. This matters precisely because any durable security architecture for Europe cannot be built around the exclusion of spoilers; it must find ways to hold them accountable within a shared framework, however contested. The Structured Dialogue offers a rare institutional space in which that tension can be managed rather than suppressed. Territorial mandate demarcation as a political survival condition Territorial status issues – for example, in relation to Crimea, Donbas, Kherson and Zaporizhzhia – must be strictly cordoned off from the operational OSCE framework. The 2014 SMM mandate achieved consensus only through contradictory Interpretative Statements on territorial issues(PC. DEC/1117), a compromise that ultimately constrained the mission’s operational reach. Any future mandate must be formulated explicitly as status-neutral. The Kosovo precedent is instructive: the OSCE Mission in Kosovo has maintained a status-neutral presence for over two decades, working across all communities, precisely because its mandate was insulated from the underlying sovereignty dispute. Entangling a future Ukraine mission in insoluble status questions will trigger the same institutional blockade that ended the Mission to Georgia in 2009. 6. Tasks the OSCE should not undertake A precise mandate is a condition of organisational survival. The Azerbaijan closure of 2015, driven by Baku’s perception that the OSCE was overstepping its operational lane, and the Belarus closures of 2002 and 2011, driven by regime resistance to political monitoring, both illustrate the same dynamic: when an organisation fails to define what it will not do, host states define it for them – by terminating the mission. For post-war Ukraine, the OSCE must proactively limit its mandate to avoid institutional overextension: → Independent ceasefire monitoring : lacking military enforcement and self-protection in a drone-heavy, 1,000 km+ frontline environment, the OSCE cannot independently monitor a ceasefire line. This requires the military protection of a robust UN or coalition mandate. → Primary security guarantees and armed peacekeeping : hard security guarantees and armed peacekeeping belong to NATO, EU Battlegroups or military coalitions. The OSCE’s scope is strictly soft-security. → War crimes prosecution and transitional justice : prosecutorial roles belong to the ICC or special tribunals. OSCE involvement in prosecution would instantly destroy any propensity for consensus required for other operations. → Economic reconstruction financing : this domain belongs to the World Bank, the IMF and the EU. The OSCE in a post-war scenario in Ukraine 5

→ Territorial status decisions : as the Transnistria, Kosovo and South Ossetia cases all confirm, the OSCE cannot govern or resolve status disputes. Its mandate must remain strictly limited to institutional capacity building. Conclusion The paper argues that the OSCE’s value in a post-war Ukraine scenario lies not in what it can lead, but in what it alone can fill: operational voids in which NATO lacks neutrality, the EU lacks reach and the UN is blocked. Its comparative advantages – field experience, normative legitimacy and an inclusive membership – are real, but fragile. The viable entry points are modular and technically grounded: demining and SALW coordination, border security management, ODIHR electoral support, HCNM minority engagement, and subsidiary monitoring under a UN or coalition umbrella. A comprehensive civilian verification mission, by contrast, is neither politically nor operationally feasible in the near term; the SMM’s record settles that question. This paper’s central warning is institutional: the OSCE’s greatest risk is not overreach but unreadiness. Four years of budgetary paralysis have eroded personnel reserves and pre-financing capacity. Planning scenarios, personnel rosters and partner coordination must begin now, before a political window opens, or the organisation will arrive too late to shape outcomes it could have influenced. The Swiss Chairpersonship’s task is to ensure that when the moment comes, the OSCE is positioned to act within a clearly demarcated lane, demonstrably leaving hard security, transitional justice, reconstruction financing and status decisions to others. About the author Fred Tanner is Member of the Advisory Board, FES Regional Office for International Cooperation in Vienna and Faculty Associate at CCDP, Geneva Graduate Institute. He is also Senior Adviser, at the Centre for Strategic Analysis(CSA), Vienna. Before that he served as Senior Advisor of the OSCE Secretary General and Director at the GCSP. General Information Publisher FES Regional Office for International Cooperation Cooperation and Peace Reichsratsstr. 13/5, A-1010 Vienna Phone:+43 1 890 38 11 205 peace.vienna@fes.de Responsible Christos Katsioulis Commercial use of all media published by the Friedrich-EbertStiftung(FES) is not permitted without the written consent of the FES. The views expressed in this publication are not necessarily those of the Friedrich-Ebert-Stiftung or of the organisation for which the author works. The Friedrich-Ebert-Stiftung e.V. holds the rights to the photographic material. Use of the photographic material is only permitted when reporting on the Friedrich-Ebert-Stiftung e.V. Commercial use of the photographic material is not permitted. If you have any questions concerning the clarification of rights, please contact the Friedrich-Ebert-Stiftung e.V. June 2026 © Friedrich-Ebert-Stiftung e.V. ISBN 978-3-98628-898-3 More publications: ↗ peace.fes.de/publications FES Regional Office for International Cooperation – Cooperation and Peace The OSCE in a post-war scenario in Ukraine 6