Book excerpt: When a nation or region prepares for public health emergencies such as a pandemic influenza, a large-scale earthquake, or any major disaster scenario in which the health system may be destroyed or stressed to its limits, it is important to describe how standards of care would change due to shortages of critical resources. At the 17th World Congress on Disaster and Emergency Medicine, the IOM Forum on Medical and Public Health Preparedness sponsored a session that focused on the promise of and challenges to integrating crisis standards of care principles into international disaster response plans.