Soviet armored units gained some combat experience during the Battle of Lake Khasan (1938), the Battle of Khalkhin Gol (1939) and the Winter War with Finland (1939–1940). But these operations and also observation of the Spanish Civil War, led People’s Commissar for Defence Marshal Voroshilov to the conclusion that the mechanised corps formations were too cumbersome. A decision was taken to disband them in November 1939, and to distribute their units among infantry. This was a mistake, as the success of German panzer divisions in France showed, and in May 1940 Voroshilov was replaced by Marshal Timoshenko. Future Marshal Zhukov had drawn different conclusions from his own experience at Khalkhin Gol and from the other battles.