chief of artillery. The other faction was led by Khalkhin Gol veterans General Georgy Zhukov of the Red Army and General Grigory Kravchenko of the Soviet Air Forces. Under this divided command structure, the lessons of the Soviet Union's "first real war on a massive scale using tanks, artillery, and aircraft" at Khalkin Gol went unheeded. As a result, Russian BT tanks were less successful during the Winter War, and it took the Soviet Union three months and over a million men to accomplish what Zhukov had managed at Khalkhin Gol in ten days (albeit in completely different circumstances). Soviet order of battle Soviet generals were impressed by the success of German Blitzkrieg tactics, but they had been tailored to conditions in Central Europe, with its dense well-mapped network of paved roads. Armies fighting there had recognised supply and communications centres, which could be easily targeted by armoured vehicle regiments. Finnish Army centres, in contrast, were deep inside the country. There were no paved roads, and even gravel or dirt roads were scarce. Most of the terrain consisted of trackless forests and swamps. The war correspondent John Langdon-Davies observed the landscape: "Every acre of its surface was created to be the despair of an attacking military force". Waging Blitzkrieg in Finland was a highly-difficult proposition, and according to Trotter, the Red Army failed to meet the level of tactical co-ordination and local initiative that would be required to execute such tactics in Finland. Commander of the Leningrad Military District Kiril Meretskov initially ran the overall operation against the Finns. The command was passed on 9 December 1939 to the General Staff Supreme Command (later known as Stavka), directly under Kliment Voroshilov (chairman), Nikolai Kuznetsov, Stalin and Boris Shaposhnikov. In January 1940, the Leningrad Military District was reformed and renamed "North-Western Front". Semyon Timoshenko was chosen Army Commander to break the Mannerheim Line. The Soviet forces were organised as follows: The 7th Army, comprising nine divisions, a tank corps and three tank brigades, was located on the Karelian Isthmus. Its objective was the city of Viipuri. The force was later divided into the 7th and 13th Armies. The 8th Army, comprising six divisions and a tank brigade, was north of Lake Ladoga. Its mission was to execute a flanking manoeuvre around the northern shore of Lake Ladoga to strike at the rear of the Mannerheim Line. The 9th Army was positioned