The United Nations are called upon in their role as guardians of world peace in connection with crises and hotspots around the globe. The appreciation of the member states for the commitment to maintaining order and security is reflected in the awarding of the Nobel Peace Prize in 1988. Unfortunately, in recent years, there have been various forms of misconduct by participants in peace missions. The contributing states are required to inform their soldiers in advance about existing codes of conduct and the consequences of violations. This book aims to discuss the resulting legal questions, particularly liability and criminal responsibility, in more detail.