 Complete the following phrase:  In 1918, following the outbreak of the Russian Revolution and the defeat of the Central Powers in World War I, Pilecki returned to Wilno at that time part of the newly independent Polish Second Republic and joined the ZHP section of the Lithuanian and Belarusian Self-Defense Militia, a paramilitary formation aligned with the White movement under General Władysław Wejtko. The militia disarmed the retreating German troops and took up positions to defend the city from a looming attack by the Soviet Red Army. However, Wilno fell to Bolshevik forces on 5 January 1919, and Pilecki and his unit resorted to partisan warfare behind Soviet lines. He and his comrades then retreated to Białystok where Pilecki enlisted as a szeregowy private in Polands newly established volunteer army. He took part in the Polish-Soviet War of 19191921, serving under Captain Jerzy Dąbrowski. He fought in the 