Global health catastrophes have complex origins, often rooted in social disruption, poverty, conflict, and environmental collapse. Avoiding them will require a new integrative analysis of the links between disease, armed conflict, and environmental degradation within a socioecological vulnerability and human security context. Exploring these connections was the aim of Avoiding Catastrophe: Linking Armed Conflict, Harm to Ecosystems, and Public Health, an expert workshop held in May 4–6, 2016, at Concordia University in Montreal, QC, Canada