Asymmetric information between conflicting parties can lead to war. During mediation, third parties often obtain private information about a conflict. This information can be used to resolve the conflict peacefully. But for this to be possible, the mediator needs to credibly communicate the information to the conflicting parties. If conflicting parties cannot believe the mediator, they do not change their behaviour. This paper solves the credibility requirement by focusing on the generation of private information during mediation. Mediation is modelled as Bayesian Persuasion. The mediator generates evidence about each conflicting party strategically and commits to sharing the obtained evidence with the respective opponent. Players can be convinced not to fight each other. The war probability is reduced and players benefit from mediation. The model stresses the relevance of the information generating process for mediation.