The Soviet invasion of Manchuria, formally known as the Manchurian strategic offensive operation (Russian: Манчжурская стратегическая наступательная операция, Manchzhurskaya Strategicheskaya Nastupatelnaya Operatsiya) or simply the Manchurian operation (Маньчжурская операция), began on 9 August 1945 with the Soviet invasion of the Japanese puppet state of Manchukuo. It was the largest campaign of the 1945 Soviet–Japanese War, which resumed hostilities between the Union of Soviet Socialist Republics and the Empire of Japan after almost six years of peace. Since 1983, the operation has sometimes been called Operation August Storm after U.S. Army historian David Glantz used this title for a paper on the subject.