For decades, Cuba has deployed doctors on medical missions around the world, often to places where skilled health workers are badly needed. These missions have a genuine humanitarian component—but they also generate billions of dollars for the Cuban government, making medical services Havana's most lucrative export.

The United States is now pressuring countries to end these agreements, threatening one of Cuba's last major sources of income. The story of Cuba's doctors therefore raises a much larger question: What is the United States actually trying to accomplish in Cuba—and what does its pressure campaign mean for the doctors and the communities they serve?

Journalist Sarah Maslin recently wrote a fascinating piece in The Economist about the precarious situation facing thousands of Cuban doctors amid the U.S. crackdown—and what it could mean for Cuba's future.