Stalin’s rivals’ biggest fault was underestimating him. He already had a history of using any means necessary to obtain what he wanted. Stalin and Leon Trotsky were two of the five members of the Politburo under Lenin. Unfortunately for Trotsky, Stalin challenged many of his decisions. Stalin’s military actions during the Battle of Warsaw (August 1920) caused four Soviet Russian armies to be routed by the Polish forces. Trotsky openly criticized Stalin at the Ninth Party Conference on September 20, 1920 thus; he was then exiled to Turkey, France, and finally Mexico for speaking ill of Stalin. In 1940 Trotsky was assassinated in Mexico, most likely by order of Stalin.
Although Lenin still thought Stalin to be an ally, the invasion of Soviet Georgia and hard line policies toward Georgians strained their friendship. Though Stalin argued with Trotsky and others, Lenin empowered him further. In 1922 Stalin was appointed General Secretary of the Communist party. This enabled him to appoint many of his allies to prominent positions. Lenin suffered a stroke in 1922 and went into semi-retirement. Stalin appeared to be