After four years of warfare, the Red Army's defeat of Pyotr Nikolayevich Wrangel in the south allowed the foundation of the Union of Soviet Socialist Republics in 1922. Historian John Erickson dates 1 February 1924, when Mikhail Frunze became head of the Red Army staff, as the ascent of the general staff, which dominated Soviet military planning and operations. By 1 October 1924 the Red Army's strength diminished to 530,000. List of Soviet Union divisions 19171945 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 Polish-Soviet War and Russian Civil War experiences. 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. The deep battle doctrine relies upon aviation and armor advances in the hope that maneuver warfare offers quick, efficient, and decisive victory. Marshal Tukhachevsky said that aerial warfare must be "employed against targets beyond the range of infantry, artillery, and other arms. For maximum tactical effect aircraft should be employed en masse, concentrated in time and space, against targets of the highest tactical importance."
Red Army deep operations were first formally expressed in the 1929 Field Regulations, and codified in the 1936 Provisional Field Regulations (PU-36). The Great Purge of 19371939 and the Purge of 19401942 removed many leading officers from the Red Army, including Tukhachevsky and many of his followers, and the doctrine was abandoned. Thus at the Battle of Lake Khasan, in 1938, and the Battle of Khalkhin Gol, in 1939, major border clashes with the Imperial Japanese Army, the doctrine was not used. It was not until the Second World War that deep operations were to be reused.
The early Red Army abandoned the institution of a professional officer corps as a "heritage of tsarism" in the course of the Revolution. In particular, the Bolsheviks condemned the use of the word officer and used the word commander instead. The Red Army abandoned epaulettes and ranks, using purely functional titles such as "Division Commander", "Corps Commander" and similar titles. Insignia for these functional titles existed, consisting of triangles, squares and rhombuses (so-called "diamonds").
In 1924 (2 October) "personal" or "service" categories were introduced, from K1 (section leader, assistant squad leader, senior rifleman, etc.) to K14 (field commander, army commander, military district commander, army commissar and equivalent). Service category insignia again consisted of triangles, squares and rhombuses, but also rectangles (1 3, for categories from K7 to K9).
On 22 September 1935 the Red Army abandoned service categories and introduced personal ranks. These ranks, however, used a unique mix of functional titles and traditional ranks. For example, the ranks included "Lieutenant" and "Comdiv" (, Division Commander). Further complications ensued from the functional and categorical ranks for political officers (e.g., "brigade commissar", "army commissar 2nd rank"), for technical corps (e.g., "engineer 3rd rank," "division engineer"), and for administrative, medical and other non-combatant branches.
The Marshal of the Soviet Union ( ) rank was introduced on 22 September 1935. On 7 May 1940 further modifications to rationalise the system of ranks were made on the proposal by Marshal Voroshilov: the ranks of "General" and "Admiral" replaced the senior functional ranks of Combrig, Comdiv, Comcor, Comandarm in the RKKA and Flagman 1st rank etc. in the Red Navy; the other senior functional ranks ("division commissar," "division engineer," etc.) remained unaffected. The arm or service distinctions remained (e.g. general of cavalry, marshal of armoured troops). For the most part the new system restored that used by the Imperial Russian Army at the conclusion of its participation in World War I.
In early 1943 a unification of the system saw the abolition of all the remaining functional ranks. The word "officer" became officially endorsed, together with the use of epaulettes, which superseded the previous rank insignia. The ranks and insignia of 1943 did not change much until the last days of the USSR; the contemporary Russian Army uses largely the same system.