 Complete the following phrase:  After the fall of the Russian Empire, Georgia became an independent republic and sought to maintain control of Batumi as well as Ardahan, Artvin, and Oltu, the areas with Muslim Georgian elements, which had been acquired by Russia from the Ottomans in 1878. The Ottoman forces occupied the disputed territories by June 1918, forcing Georgia to sign the Treaty of Batum. After the demise of the Ottoman power, Georgia regained Ardahan and Artvin from local Muslim militias in 1919 and Batum from the British administration of that maritime city in 1920. It claimed but never attempted to control Oltu, which was also contested by Armenia. Soviet Russia and Turkey launched a 