 The Japanese force stalemated with the Soviet Union's Red Army in the Battle of Lake Khasan in 1938, and lost the decisive Battle of Nomonhan in 1939, during which time it sustained heavy casualties.After the "Nomonhan incident", the Kwantung Army was purged of its more insubordinate elements, as well as proponents of the "Hokushin-ron" ("Northward Advance") doctrine who urged that Japan concentrate its expansionist efforts on Siberia rather southward towards China and Southeast Asia.The Kwantung Army was heavily augmented over the next few years, up to a strength of 700,000 troops by 1941, and its headquarters was transferred to the new Manchukuo capital of Hsinking.