Globalization, migration of the population, climate change, and war and other conflicts throughout the world have created an increasingly complex environment for humanitarian aid and international response and relations. In the past two decades, wars and other conflicts have increasingly become an internal problem for fragile nation-states, and these disrupted states often suffer from inequalities in social, economic, and political development, exacerbated by long-term ethnic, religious, and minority conflicts and by the fierce competition for existing resources. In the meantime, these animosities become an international problem to solve. The humanitarian response to war-related crises and disasters has gradually evolved from charitable but uncoordinated efforts into more systematized interventions. Large, multinational organizations have developed significant technical and logistical capacity in responding to the public health needs of large vulnerable populations. The authors analyze the current controversies and future prospects in complex humanitarian emergencies management.