For half a century, the most important diplomatic documents on the history of Soviet-German relations on the eve of the Great Patriotic War have been kept in strict secrecy in the archives of the Ministry of Foreign Affairs. Official publications of documents of the USSR Foreign Ministry as conspiratorial stop at the fateful date - August 1939. And not by chance. It was this month that a non-aggression pact was signed between the Soviet Union and Hitler's Germany.