It was the never-ending stream of news content on Edvards Puharts’ iPhone that propelled him to sign up for military conscription in Latvia. “I was panicked,” the 20-year-old told Euronews.

Latvia reintroduced compulsory military service for adult males on January 1 last year, having abolished it in 2006. The Baltic country shares a 180-mile border with Russia to its east and is ...