Following the failure of both the traditional Western bloc as well as the United Nations in sustaining the post-1945 order, the international system is now in flux, and it remains unclear what a new international order might look like. As the two world wars have demonstrated, it is possible that it will emerge after open conflict. In addition, globalization has led to the emergence of a swathe of non-traditional challenges, such as environmental security, energy security, terrorism, cybersecurity, food security and pandemics. Furthermore, it is also entirely plausible that existential threats to states, societies and even humanity, could occur as a result of unexpected “black swan” developments, such as threats arising from the emergence of new technologies, artificial intelligence, the sudden outbreak of nuclear conflict, and even unidentified anomalous phenomenon,  highlighting the broad array of security challenges that the world faces today. The De Gruyter Handbook of GlobalSecurity Challenges provides a state-of-the-art survey of current research and emerging questions on a range of challenges that the international community is facing. This volume clarifies the nature of the challenges, explains the current state of literature, suggests solutions or better strategies for management, and suggests the research agenda for the coming years.