deserters to compel their surrender; one in ten of those returning was executed. The same tactic also suppressed peasant rebellions in areas controlled by the Red Army, the biggest of these being the Tambov Rebellion. The Soviets enforced the loyalty of the various political, ethnic, and national groups in the Red Army through political commissars attached at the brigade and regimental levels. The commissars also had the task of spying on commanders for political incorrectness. Political commissars whose Chekist detachments retreated or broke in the face of the enemy earned the death penalty. In August 1918, Trotsky authorized General Mikhail Tukhachevsky to place blocking units behind politically unreliable Red Army units, to shoot anyone who retreated without permission. In 1942, during the Great Patriotic War (1941–1945) Joseph Stalin reintroduced the blocking policy and penal battalions with Order 227. The Red Army controlled by the Russian Soviet Federative Socialist Republic invaded and annexed newly independent states of the former Russian Empire, incorporating them into the Soviet Union. Polish–Soviet War and prelude The Soviet westward offensive of 1918–19 occurred at the same time as the general Soviet move into the areas abandoned by the Ober Ost garrisons that were being withdrawn to Germany following the end of World War I. This merged into the 1919–1921 Polish–Soviet War, in which the Red Army invaded Poland, reaching the central part of the country in 1920, but then suffered a resounding defeat in Warsaw, which put an end to the war. During the Polish Campaign the Red Army numbered some 6.5 million men, many of whom the Army had difficulty supporting, around 581,000 in the two operational fronts, western and southwestern. Around 2.5 million men and women were mobilized in the interior as part of reserve armies. Reorganization The XI Congress of the Russian Communist Party (Bolsheviks) (RCP (b)) adopted a resolution on the strengthening of the Red Army. It decided to establish strictly organized military, educational and economic conditions in the army. However, it was recognized that an army of 1,600,000 would be burdensome. By the end of 1922, after the Congress, the Party Central Committee decided to reduce the Red Army to 800,000. This reduction necessitated the reorganization of the Red Army's structure. The supreme military unit became corps of two or three divisions. Divisions consisted of three regiments. Brigades as independent units were abolished. The formation of departments' rifle corps began. Doctrinal