The book "Collective Security within Reach" by Sovaida Ma'ani Ewing discusses the concept of global collective security and critiques current global security policies. It highlights the inadequacies of existing security arrangements in the face of modern threats like cyber attacks and genocide. The book proposes principles for collective security based on justice, cooperation, and international cooperation. It reviews past efforts towards collective security by the United Nations and suggests institutional reforms for a more effective global security system.