Inspired by the practice turn in the field of international relations, this article contributes to the growing interest in the sociological and potentially transformative nature of the concept of human security, with a specific emphasis on the protection of civilians affected by armed conflict. Drawing on fieldwork conducted in Cambodia and Myanmar on the protection of children affected by armed conflict, it argues for a fresh analysis of human security through the lens of a 'politics of protection'. By mapping the work of international, government, and non-governmental actors involved in the protection of conflict-affected populations, the article shows that the distinction between welfare/development-oriented approaches and security-oriented approaches creates a protection gap for vulnerable populations in practice. This brings into question the salience of a security-development nexus conceptualization of human security. Instead, a politics of protection lens offers an alternative starting point for the study of security practices in conflict-affected societies, and facilitates a reconceptualization of human security as a transformative approach to contesting the politics and practice of civilian protection.