RESUMO
Many countries show a growing willingness to use militaries in support of global health efforts. This Series paper summarises the varied roles, responsibilities, and approaches of militaries in global health, drawing on examples and case studies across peacetime, conflict, and disaster response environments. Militaries have many capabilities applicable to global health, ranging from research, surveillance, and medical expertise to rapidly deployable, large-scale assets for logistics, transportation, and security. Despite this large range of capabilities, militaries also have limitations when engaging in global health activities. Militaries focus on strategic, operational, and tactical objectives that support their security and defence missions, which can conflict with humanitarian and global health equity objectives. Guidelines-both within and outside militaries-for military engagement in global health are often lacking, as are structured opportunities for military and civilian organisations to engage one another. We summarise policies that can help close the gap between military and civilian actors to catalyse the contributions of all participants to enhance global health.