One Tuesday morning last month, a 15-year-old Russian boy got ready for school by packing a paramilitary vest, a helmet, and a knife. Before leaving his house, he sent a manifesto to his classmates denouncing gay people and Jews, and quoting a mass murderer along with a white-supremacist conspiracy theory. When the boy, identified by prosecutors as Timofey K., arrived at his school, located outside Moscow, he went to the bathroom to put on his gear, which he’d branded with neo-Nazi symbols and