In the early 1930s the military threat in the Far East was continuously growing. The plans for preparing war against the USSR were the main elements of the Japanese military policy. Anti- soviet propaganda overflowed both Japan and Korea, and had an openly hysterical character. The military conflict at the Lake Hassan in July 24, 1938, unleashed by the Japanese side, became apogee of that hysteria. Information war in the Soviet Union, directed against Japan, had its results. In particular, the deportation of Koreans from the territory of Far East in 1937 can be considered "an unarmed action". This report based on declassified materials of the Russian State Military Archives presents the analysis of the situation at the Soviet-Manchurian border in 1935 - 1936 on the eve of events outlined.