This editorial explores the complex and evolving relationship between law, peace, and the military in the modern context. It analyzes how changing security threats, aspirations for peace, and the need for legal legitimacy constantly reconfigure this fundamental nexus, especially in countries affected by conflict. The expanded roles of the military beyond traditional defense are discussed, including peace operations, stabilization, and response to civil emergencies. The editorial underscores the critical importance of compliance with International Humanitarian Law (IHL), International Human Rights Law (IHRL), and national legal frameworks for operational legitimacy and effectiveness, arguing that respect for the law is essential to achieving sustainable peace.