During the civil war, he was a leader of the Military Opposition, who opposed the presence of thousands of former officers of the Imperial Army in the newly created Red Army. At the 8th Party Congress of the Russian Communist Party, Smirnov appeared as a delegate from the 5th Army. On 20 March 1919, he gave a speech to the Congress on the use of former Tsarist officers (termed "Specialists" within the party) and of political commissars in the Red Army. Responding to accusations from Grigory Sokolnikov that he opposed the use of officers, which by this point had become a key part of Bolshevik military strategy, he denied favouring the use of partisan militias in the Russian Civil War. He did, however, warn of the inadequate political mechanisms that the Soviet authority had at its disposal to control the officer-specialists. Arguing for the repeal of "Decree on Revolutionary Military Councils", he said to the Congress: