Fiber-optic drones popped up on the battlefields of Ukraine last year, and are set to become more popular on both sides in 2025.

The troops are exposed, green, loyal—and dying by the thousands in front-line combat against Ukraine.

Find out in our guide. How did children help in World War One? How did children use farming, collections and jobs to help in World War One? Find out in our guide. What did people eat during World ...