It is perhaps the single most elusive question today—how to manage and care for the billions of people who will fall ill this year, often terminally, in nations rich and poor? In so many cases the status of health is a purely financial question. Far too often poor health is simply a question of igno- rance or the absence of drugs, medical facilities, clean water and a healthy environment. To help in-  form the debate, World Policy Journal asked a panel of experts to weigh in on what they see as the most pressing health crisis today and how it can be solved.