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