In the Spring 2010 issue of City Journal, I described an archive of documents from Soviet government agencies smuggled to the West by the Russian researcher Pavel Stroilov and the Soviet dissident Vladimir Bukovsky. These documents, I noted, were available to anyone who wanted to consult them. But nobody did. Publishers were indifferent. Only a fraction of the documents had been translated into English. This was, I argued, a symptom of the world’s dangerous indifference to the enormity of Communist crimes. Within weeks of the article’s appearance, I received hundreds of e-mails. Many came from victims of Soviet Communism—there is...