When Hemil Mangukiya left his small village in the Indian state of Gujarat last December, he told his family he was off to Russia to make a better living than was possible at home in India. Lured by a recruitment video he had seen on YouTube, the 23-year-old had thought he was going for a secure security job far from the war in Ukraine. But in strained phone calls home from Russia, he told his family he was instead sent to a month-long military training camp and then taken to the frontlines, where he was made to dig trenches, carry...