UN Charter Art.33 points to means such as negotiation, mediation and arbitration to settle disputes and to avoid the risk of use of force. Judgments of the International Court of Justice are of great value also to further develop international law. However, courts are hardly ever employed to save peace by the judicial settlement of big disputes. Following the precedent of the Nuremberg tribunal, special tribunals have been set up to try war crimes. Even more important, an international criminal court has been established. Fact-finding (termed ‘enquiry’) has achieved a prominent role both to solve and to prevent conflicts. Thus, the safeguards system of the IAEA using inspectors, cameras and satellites and environmental sampling continuously verifies that no fissionable material is diverted away from peaceful uses. With much fake news around, impartial professional inspection, monitoring and reporting – for instance, about the use or possession of chemical weapons – has become more important. Diplomacy seeks to secure or create peaceful relations by agreement, precluding or removing the threat or use of force. Examples are given of successes of diplomacy to preserve peace as well as of failures and of talks going forever without result.