EDITOR—Women and children continue to die needlessly in developing countries. We know the causes but seem powerless to prevent their deaths. Constraints within health systems are blocking improvements, and we don't know enough about how to strengthen and sustain them without external investment. Individuals and communities have their own priorities for health, and a global solution for disease and poverty is impossible to prescribe.

A village was asked by an aid agency what its priorities for development aid would be, the answer presumed to be a health …