Relationship dossier
Croatia
Slovenia
Relationship assessment
Practical cooperation coexists with a long-running dispute over the border and the status of the 2017 arbitration award.
Croatia toward Slovenia
-20Croatia agreed to international arbitration on the border in 2009, then withdrew from the process in 2015 and rejects the 2017 award. Croatia also participates with Slovenia in the jointly owned Krško nuclear power plant.
Slovenia toward Croatia
-20Slovenia regards the 2017 arbitration award on the border as binding and has pressed for its implementation. Slovenia also participates with Croatia in the jointly owned Krško nuclear power plant.
Overall relationship
+5The relationship combines a durable, concrete energy partnership through the jointly owned Krško nuclear power plant with a serious and unresolved border dispute. The arbitration process and its rejection by Croatia have sustained tension, while Slovenia’s insistence on implementing the award has kept the issue central to bilateral relations.
How to read these scores
Scores are rough judgments, not objective measurements or current verification. Directional scores describe government policy and conduct, not public opinion. The overall score is an independent estimate, never an average.
- −100
- Extreme sustained hostility
- −50
- Substantially adversarial
- 0
- Mixed or neutral, supported by knowledge
- +50
- Substantially cooperative
- +100
- Exceptionally close sustained partnership
“Not assessed” means there is no recorded score. Pair existence makes no claim about diplomatic recognition or established relations.
Relationship context
Overview
Croatia and Slovenia maintain practical cooperation, including a jointly owned nuclear power plant, but their relationship has been persistently strained by the unresolved border dispute. Croatia withdrew from the arbitration process and rejects the 2017 award; Slovenia regards the award as binding. The dispute has periodically affected broader bilateral relations and Croatia’s EU accession process.
Areas of tension
- The two governments disagree over the land and maritime border, including the Bay of Piran.
- Croatia rejects the 2017 arbitration award, while Slovenia considers it binding and seeks its implementation.
Key developments
Croatia and Slovenia agreed to submit their border dispute to international arbitration.
Croatia withdrew from the arbitration process, citing Slovenia’s conduct during the proceedings.
The arbitral tribunal issued its award on the Croatia–Slovenia border dispute; Slovenia accepted it as binding, while Croatia rejected it.
The two countries established a jointly owned arrangement for the Krško nuclear power plant.
Major uncertainties
- The extent of current practical cooperation beyond the Krško nuclear plant is unclear.
- The prospects for resolving the border dispute remain uncertain.