The U.S. and NATO have long maintained that thousands of Russian troops are fighting alongside separatists inside eastern Ukraine, and that the Russian government is obscuring not only the presence but also the deaths of its soldiers there. In March, NATO Deputy Secretary General Alexander Vershbow told a conference, “Russian leaders are less and less able to conceal the fact that Russian soldiers are fighting — and dying — in large numbers in eastern Ukraine.”

Hence the extreme measures to get rid of the evidence. “The Russians are trying to hide their casualties by taking mobile crematoriums with them,” House Armed Services Committee Chairman Mac Thornberry told me. “They are trying to hide not only from the world but from the Russian people their involvement.”

Thornberry said he had seen evidence of the crematoriums from both U.S. and Ukrainian sources. He said he could not disclose details of classified information, but insisted that he believed the reports. “What we have heard from the Ukrainians, they are largely supported by U.S. intelligence and others,” he said.