The U.S. troop withdrawal from Afghanistan is imperiling the 3-decade global quest to eradicate polio. The Taliban, which now controls large swaths of the country, has blocked house-to-house polio vaccination in areas under its reign the past 3 years, putting up to 3 million children out of reach of the campaign. The Taliban may well wrest complete control from the Afghan government—which supports the eradication campaign—after U.S. forces are gone. But some inside and outside the Global Polio Eradication Initiative say a clear resolution to the conflict, regardless of who prevails, may actually aid eradication efforts. They hope the campaign will be able to work with the Taliban to keep vaccinations going if it consolidates power.