ICCWS 2021 is an opportunity for academics, military personnel, practitioners and consultants from around the world who are involved in the study, management, development and implementation of systems and concepts to combat information warfare or to improve information systems security to come together and exchange ideas. There are several strong strands of research developing in the cyber warfare and cyber security area including the understanding of threats and risks to information systems, the development of a strong security culture, as well as incident detection and post incident investigation. New threats brought about by social networking and cloud computing are gaining interest from the research community and the conference is tackling these issues.