In the Russian part of Ukraine Symon Petliura tried to defend Defending and strengthen Cause_change_of_strength the Ukrainian People 's Republic but as the Bolsheviks began Process_start to win the Russian Civil War , they started Process_start to advance Cause_to_make_progress westward towards the disputed Ukrainian territories , causing Causation Petliura 's forces to retreat Escaping to Podolia .

After this success , Kalinowski marched Self_motion deeper into Podolia , seizing Conquering several towns , such as Szarogrod , Jampol and Skinderpol .