 The list of Soviet Union divisions 1917–1945 details the formations of the Red Army in that time.In the late 1920s and throughout the 1930s, Soviet military theoreticians – led by Marshal Mikhail Tukhachevsky – developed the deep-operations doctrine, a direct consequence of their experiences in the Polish-Soviet War and in the Russian Civil War.To achieve victory, deep operations envisage simultaneous corps- and army-size unit maneuvers of simultaneous parallel attacks throughout the depth of the enemy's ground forces, inducing catastrophic defensive failure.