Lenin and the Bolsheviks had used War Communism, built around complete nationalization of the economy and forced requisitions from the peasantry, to fight the Civil War. Events in 1921 forced them to rethink that. A stubborn and persistent peasant uprising around Tambov required 40,000 soldiers and the use of poison gas to suppress. On 28 February 1921, the sailors of the Kronstadt naval base mutinied against Bolshevik excesses and had to be suppressed by a bloody infantry assault over the frozen waters of the Gulf of Finland. Lenin became convinced something had to change, and beginning with the Tenth Party Congress of March 1921, he launched the New Economic Policy (NEP). This replaced forcible requisitions of grain with a moderate tax in kind and returned food production, consumer goods, and retail trade to private hands. While this was a necessary step toward economic recovery, Bolshevik veterans of the Civil War resented its concessions to peasants and businessmen- enemies of the revolution.
In the first years after the Civil War, the Soviet Union was an international pariah, its calls for the revolutionary overthrow of foreign governments putting it outside the community of nations. It turned to Germany, another pariah, as a natural ally. From 1922, the two exchanged military advice and technology, with Germany providing weapons designs and expertise, and the Soviet Union providing space to experiment with weapons systems Germany was denied by the Treaty of Versailles. The German laboratories and schools in the Soviet Union were, however, never large, and the Soviet Union bought plans and technology from all Western powers.
Trotsky continued to run the Red Army after the end of the Civil War and used peace to build an army closer to revolutionary ideals. During initial demobilization in spring 1920, before this was interrupted by the Polish War, he transformed armies into labor armies, intended for economic reconstruction. After the end of the Civil War, he slowly shifted toward a militia as more in keeping with socialist ideals than a standing army. While the upheavals of 1921 showed the danger of rapidly moving to a popular militia, Trotsky maintained experimental militia units in industrial centers. In 1923 he began the large-scale transformation of standing units into militia to reduce expenditure and bring the army closer to the Soviet people. By the mid-1920s, over half the Red Army's divisions were part-time militia.
The Red Army's self-image as a revolutionary institution involved the abolition of traditional military hierarchies. The very word "officer" was regarded as bourgeois and was replaced by "commander." Titles of rank were abolished and replaced with functional designations: instead of "general," for example, Red Army commanders were called "brigade commander"-kombrig-or "division commander"-komdiv. Uniforms were deliberately spare, devoid of the braid and epaulets of other armies. Its new officer corps was remarkably homogenous. It had some Red Commanders-revolutionaries turned commanders, and devoid of formal military training. It also retained a number of military specialists- officers of the prewar tsarist army. Its most important element, though, lay in between. The First World War had created a large number of Russian officers, commissioned and noncommissioned, and those wartime officers were the bulk of the Red Army's officer corps. While possessed of some military experience and formal training, they were not tied to the old regime and old elites the way pre-1914 officers were. After the Civil War, Trotsky began slowly returning autonomy to these safely revolutionary commanders while reducing the authority of commissars. Trotsky also experimented with unusual accommodations to the Soviet Union's multiethnic population. The Red Army created national formation: homogenous units of non-Russians trained and commanded in their native language by native officers. At their height, these accounted for 10 percent to 15 percent of the Red Army's manpower.
Trotsky's management of the Red Army was undermined by a struggle for political power. Lenin suffered the first of a series of strokes in May 1922, unleashing a fight over who would succeed him as head of the Bolshevik Party. The other members of the ruling Politburo, most notably Stalin, saw Trotsky as their most dangerous rival. His reputation as victor in the Civil War, his control over the Red Army, and his arrogance created a broad alliance against him. In autumn 1923, as Germany was gripped by hyperinflation and seemed close to revolution, Trotsky prepared the Red Army for military intervention through Poland to protect any potential German revolutionary government from destruction. Trotsky was forced to demand and use extensive economic powers to prepare the Soviet Union for war, thus confirming the accusation of being a potential dictator that his opponents leveled against him. In early 1924, a concerted attack began on Trotsky's key subordinates, replacing Trotsky's deputy Efraim Markovich Sklianskii with Frunze, allied to Trotsky's opponents. Trotsky was gradually pushed out of the Red Army and resigned at the beginning of 1925. Frunze spent less than a year as formal head of the Red Army before dying during an operation in October 1925. He was replaced by Kliment Efremovich Voroshilov, a thorough mediocrity devoid of civil or military education. His sole qualification was his slavish obedience to Joseph Stalin, who was methodically defeating all rivals to become chief authority in the Soviet Union.
This NEP Red Army, built on Trotsky's model and reliant on First World War technology, was tested under fire in a brief border war with China. In October 1929, the Red Army intervened in Manchuria to protect Soviet interests, particularly in the strategically vital Chinese Eastern Railway. The Red Army was remarkably successful, defeating local Chinese forces handily and withdrawing after this demonstration. The Soviets also successfully employed their first domestically built tanks, variants on a Renault model.
While the Red Army of the 1920s saw numerous cases of political repression, it was an institution of astounding intellectual ferment and creativity. The revolution's destruction of old elites and the Bolsheviks' self-conscious identification as the party of the future produced a remarkable flowering of military thought and debate. Frunze had argued that technological developments made it necessary to organize the entire state for war. The mobile fronts of the Civil War and the Bolshevik conviction that war brought revolution combined to produce a general emphasis on offensive, mobile warfare. Tukhachevskii, as a writer, theorist, and briefly the Red Army's Chief of Staff, promoted this new vision. Much of the actual theoretical work was done by Tukhachevskii's protégé Vladimir Kiriakovich Triandafillov. He formulated a concept of shock armies, reinforced with tanks and artillery, attacking in echelons to break through enemy defenses and to carry out deep encirclements. Operations would not stop with the breakthrough, but continue to further operations to pursue and finally destroy the enemy. Triandafillov's ideas served as the seed for mature Soviet doctrine as implemented in World War II and carried through the Cold War. By 1936, a scheme of combining infantry, tanks, artillery, airborne troops, and aviation to attack the full depth of enemy defenses simultaneously-deep battle-was codified into official doctrine in the Red Army's field manual.