 After the October Revolution, they continued to have differences.Whereas Lenin believed that all countries across Europe and Asia would readily unite as a single state following proletariat revolution, Stalin argued that national pride would prevent this, and that different socialist states would have to be formed; in his view, a country like Germany would not readily submit to being part of a Russian-dominated federal state.Stalin biographer Oleg Khlevniuk nevertheless believed that the pair developed a "strong bond" over the years, while Kotkin suggested that Stalin's friendship with Lenin was "the single most important relationship in Stalin's life".