VELYKYI BURLUK, Kharkiv Oblast — War veteran Serhii Chepurnyi recently turned 40. This year, he didn't celebrate his birthday. His hands shaking as he took a cigarette from its pack, Chepurnyi carefully chose his words as he recalled what Russian soldiers did to him when occupying his native village, Velykyi Burluk. Velykyi Burluk, located roughly 50 kilometers from the Russian border, was swiftly occupied when Russia launched its full-scale invasion of Ukraine on Feb. 24. The small settlement was officially liberated on Sept. 12. A few days earlier, Chepurnyi was freed from a torture chamber in Vovchansk, located within just...