Breaking the Mannerheim line: Soviet Strategic and Tactical Adaption in the Finnish-Soviet Winter War,

Franz-Stefan Gady, senior fellow with the Institute for International Strategic Studies

[…] What had been initially thought of as a mere police action by the party apparatchiks — Stalin himself said that it would not take longer than two weeks — turned quickly into military stalemate for the Red Army. 

Four armies consisting of 21 Soviet divisions of the Soviet Leningrad Military District, a total of 450,000 troops, invaded Finland on the morning of Nov. 30, 1939 on eight main axes of advance along the 800-mile long Finnish-Soviet border without a formal declaration of war. Finnish troops, under the command of Field Marshall Carl Gustaf Emil Mannerheim, a former Tsarist officer, inflicted a stunning first defeat on the Red Army in the Battle of Tolvajäri on December 12.  […]

His (Timoshenkos) attack scheme for the Mannerheim Line consisted of the following: a massive but well-coordinated artillery barrage that would precede a combined arms attack of armor, supported by infantry, with close air support held in reserve. Once the armor pierced the frontline — contrary to the incentives of Soviet Deep Battle doctrine, which was focused on achieving a decisive breakthrough via combined arms assaults, using reserves to exploit breakthrough in order to destroy enemy centers of supply and communication in depth — it would not outrun the supporting infantry and artillery and break into the rear. Instead, armor would wait and help expand the breach while follow-on waves of assault troops were sent in. If an attack was repulsed, the Red Army would simply shift its attack to another sector of the narrow Karelian Isthmus frontline, slowly grinding down Finnish defenses.[…]

Looking for potential lessons from the Winter War for Ukraine today, a major takeaway is that a relatively untrained, tactically badly led, and ill-equipped conscript force can indeed strategically, organizationally, and tactically adapt under the right leadership. Such a force can achieve a level of proficiency at all three levels sufficient enough to ultimately militarily prevail against a more highly motivated, tactically superior (although the Finnish Army never mastered combined arms operations at scale and, while good at counterattacks, generally underperformed on the offense), if outnumbered and poorly equipped adversary. However, as one commentator put it: “[Russian President Vladimir] Putin has yet to find his 21st century Timoshenko” to facilitate such a rigorous top-down adaptation process in the Russian military currently fighting in Ukraine. Läs artikel