The war between Russia and Ukraine stillrages on after three and a half years. More than one and a half millionsoldiers have died or been wounded. There are nearly daily attacks on Ukrainiancities. Millions of people have migrated, especially from and within Ukraine.The economies in both countries, but also in Europe and beyond have sufferedsubstantially. The West has spent $300 billion on economic and military supportfor Ukraine. Other major threats, such as global warming, have disappeared fromthe priority list.
Just like the war that began in 1914 andended four years later and also the Second World War that ended in five years,the Russia–Ukraine war will also end at some point, hopefully in the not-too-distantfuture. Since 2025 there have been diplomatic efforts to stop the war, with theUnited States as mediator. But little thought seems to be going in to thepost-war period. This paper tries to fill this gap by asking how the Europeansecurity order could be imagined once the fighting has stopped.
More particularly, it might be asked which(regional) international organisations could and should play a role in fillingthe void after the war. International organisations give rise to order and stabilityas they require cooperation on a daily basis. Another advantage of institutions(and international regimes in general) is that they do not immediately fallapart once a problem arises. Due to long-term cooperation, there is a certainlevel of respect and trust between the member states that can act as guardrailsin times of conflict.
Although directly involved, Europeangovernments have not yet raised the issue of the future European security order.They tend to be busy supporting Ukraine and at the same time building up theirown defences, within the framework of both NATO and the EU. There seems to be ageneral fear that Russia may attack NATO and EU members, once the war inUkraine comes to a standstill (or even before). The default position in Europeanand Russian thinking about the future is that Europe will be split into twomajor blocs: a Western bloc (including Central and Eastern Europe) versusRussia and some of its neighbours (including Belarus).[1]Similar to the Cold War, the two blocs may be separated by an «Iron Curtain», thistime stretching from the Arctic to the Caucasus, living apart from each other. Inthe same vein, it is believed that we may enter an era of protractedconfrontation with Russia. Some observers even recommend a new containmentpolicy for Europe vis-à-vis Russia.[2]
The aim of this paper is to show thatthere are alternative, more inclusive scenarios. The end of the Ukraine–Russianwar could be a historical turning point. Such moments in history open up thepossibility to try to do things better than before. That will at least be theaspiration of many people on both sides of the ceasefire line. Under thosecircumstances, governments sometimes do manage to shift to a more stablesecurity constellation (examples are the periods after 1815 and 1945);sometimes, they fail (as in 1918 and 1989). Remarkably, in the successful casesthe loser of the war was included in the security order. Mutatis mutandis, whenthe loser was not included, it yielded a new period of instability and war.
This paper starts with a more analyticalpart that describes the differences between two fundamentally different typesof security constellation: balance of power and collective security. Second, whatwould a peace agreement between Ukraine and Russia look like? In the third part,the question is raised of what the post-war security constellation in Europe wouldlook like. What role is left for NATO, the Collective Security TreatyOrganization (CSTO), the Organization for Security and Cooperation in Europe (OSCE),and the EU? Where would Ukraine fit in? And what about Russia?
[1] Ilya Budraitskis and Greg Yudin (2024): Overcomingthe rivalry between military blocs in Europe, in: IGRec Policy Papers,2024.
[2] Max Bergmann (and others) (2025): ALong-term Russia Strategy for Europe. Back to Containment?, in: CSIS report,July.
