This edited volume is published during a time of fundamental uncertainty in our world. Gone are the days when policymakers and researchers could rely on stability to provide explanations of conflict as a consistent, focal reference point in the international system. While the behaviour of states is still influenced by anarchy, the early twenty-first century world is hardly stable. The combination of climate change, forced migration and COVID-19 crisis continues to create a world in flux with the most vulnerable too close to the dangers of life-threatening natural disasters or sea journeys to flee the prospect of physical harm and far removed from the promise of a vaccine.

This unevenness in protection and access, which defines the fragility of life on planet Earth, prompts us to consider the disparities that are the result of new technologies and their applications throughout our world. The main reason we introduce three alternative levels of analysis to those in Waltz’s Man, the State, and War is to explore the changing nature of agency as a counter to structure, identity as a reference in relation to sovereignty and peace as more than the absence of war. Waltz’s images, as well as his assertion as a defensive realist that states can never have enough security, are that conflict may be understood to be caused now and always by human nature, the state and the international system. His third image, the international system, as the privileged level of analysis in a neorealist environment defines the literature in the Western core of international relations.