The 1992 book "The Sword and the Shield: The Mitrokhin Archive and the Secret History of the KGB", by Christopher Andrew, based on the Mitrokhin Archive smuggled out of Russia in the early 1990s by a KGB archivist, contains information about wartime Soviet knowledge of Japanese enciphered transmissions. It claims that the Soviets independently broke into Japanese PURPLE traffic (as well as the Red predecessor machine), and that decrypted PURPLE messages contributed to the decision by Stalin to move troops from Far Eastern Asia to the area around Moscow for the counterattack against Germany in December 1941 as the messages convinced the Soviet government that there would not be a Japanese attack.