Fifteen minutes before midnight, a young Russian conscript named Danila, who had been sent to fight in Ukraine, picked up his phone to write a message to his family and friends back home in a small town in the Samara region. It was 31 December. “We congratulated each other, wished each other the best for the new year, and then he was gone,” said a close friend who wrote with him that night. Minutes later, a US-made Himars rocket slammed into Professional Technical School No. 19 in Makiivka, a city in eastern Ukraine under Russian occupation. It took nearly 50...