He took part in seven raids by the guerrilla brigade of Sydir Kovpak. Though he did not achieve his dream of a career as a military pilot he graduated from the Moscow Border Communication College. He entered action on June 22, 1941 as a Soviet border guard on the border with Romania and witnessed the tragic encirclement and routing of Soviet forces near Kiev. He would come to spend years deep behind enemy lines where he took guidance from Soviet guerrilla leaders in Ukraine including Sydir Kovpak, Semyon Rudnev and Pyotr Vershigora.
- "Ушел из жизни Герой Советского Союза Петр Евсеевич Брайко — gosobzor.ru". 7 April 2018. Retrieved 9 April 2018.