Along with the redefining of state values as a response to changes in the grounds for conducting war, a relatively new principle called the protection of nationals abroad has arisen, descending from an increased number of state interventions justified on behalf of their nationals abroad. This book aims to offer a pertinent research of the above principle and explore the ways of its justification from the normative perspective, specifically through the Just War Theory lens. The central argument of the research is based on the analogy between the primary principle of jus ad bellum, the right to national-defence and protection of nationals abroad. In order to demonstrate the link, two ends of sovereignty and national-defense are discussed: community life and individual rights. The book shows that considering community values as principal goods of state sovereignty cannot justify protection of nationals abroad. Subsequently, it is argued that the sole way of normative justification stems from the individualistic approach that conceives the idea of the state in its duty to ensure well-being of its nationals.