There is an urgent need for global cooperation, leadership, and sustainable financing to address critical gaps in health preparedness as revealed by the World Health Organization (WHO)’s Joint External Evaluation (JEE). Writing in BMJ Global Health, experts at Resolve to Save Lives highlight the results of WHO’s JEE process, in which 100 countries assessed their ability to handle epidemics and ultimately identified over 7,000 priority actions to address critical gaps. Despite these diagnoses, few actions have been addressed, exposing significant vulnerabilities in global health systems. We emphasize the urgency of strengthening core capacities such as laboratory surveillance and workforce training, as well as the need for global coordination, donor support, and effective leadership to ensure readiness for future outbreaks, as well as more sustainable, long-term financing to bolster public health infrastructure.