For almost 80 years, the version about the involvement of the Soviet Union in the execution of Poles in the Katyn Forest near Smolensk has been widely circulated. American professor (Montclair University, USA) Grover Furr, when he began writing this book, did not doubt the official version of the Katyn tragedy, which blamed the Stalinist regime for the execution of several thousand Polish citizens. But later, when he tried to study the evidentiary part of these accusations, serious inconsistencies arose in widely circulated facts that required additional study. And this led the author to a clear position: the official version of the Katyn massacre is the result of a large-scale falsification by Goebbels, aimed at causing a split between the allies on the eve of the Tehran Conference.