Lenin's promise of self-determination was fulfilled by his Decree on Nationalities in November 1917 due to the weakness of Bolshevik power in these areas.
Several areas wanted full independence from Russian control, including Finland, Ukraine and Georgia.
As a Georgian himself, Stalin seemed a natural choice to become Commissar for Nationalities in the new Bolshevik government.
The Civil War complicated the situation as it provided a further opportunity for the national minorities to gain greater self-government.
Finland and the Baltic States gained independence in the Civil War which lasted until World War Two during which the USSR only regained the Baltic States back.
Georgia was under the control of the Mensheviks during the Civil War and also seemed likely to declare independence.
Stalin's heavy-handed methods to keep control of Georgia shocked Lenin but ultimately, alongside other important areas such as Ukraine, it remained under Russian Communist control.