By many measures, South Korea’s healthcare system is among the most successful in the world. Seeing a doctor is easy. The mortality rate from preventable illnesses is low. And though most hospitals and clinics are privately run, a nationalized single-payer health insurance program keeps costs affordable. An appendectomy costs $2,500 — less than a fifth of the average price that one pays in the United States for example — with 80% of that covered by government insurance. But a four-month-old strike by more than 9,000 medical residents and interns across the country is turning the public against…