With little room to surge during a crisis, America’s health-care system operates on the assumption that unaffected states can help beleaguered ones in an emergency. That ethic works for localized disasters such as hurricanes or wildfires, but not for a pandemic that is now in all 50 states. Cooperation has given way to competition; some worried hospitals have bought out large quantities of supplies, in the way that panicked consumers have bought out toilet paper.