He did his stint in cavalry,[1] but in 1913 he began formal training as a pilot and graduated at the beginning of World War I from Gatchina military aviation school.

On 31 March 1915 Alexander Kazakov successfully repeated the aerial ramming attack first attempted by Pyotr Nesterov, using a Morane-Saulnier G as his piloted projectile.

[3] Five months later, Kazakov resumed his winning streak with his sixth victory on 6 May 1917, which was shared with Ernst Leman and Pavel Argeyev.

[1] During the Russian Civil War Kazakov joined the Slavo-British Allied Legion in Arkhangelsk and fought against the Workers' and Peasants' Red Air Fleet.

[2] On 1 August 1918 Kazakov became a major in the Royal Air Force and was appointed to be commanding officer in charge of an aviation squadron of the Slavo-British Allied Legion made up of Sopwith Camel planes.