Robert M. Kennedy, CMH Publication 104-18German Antiguerrilla Operations in the Balkans…
“ Occupied for centuries by Romans, Turks, Austrians, and Hungarians, the Balkan peoples were forced to adopt the methods of irregular warfare in the struggle against their oppressors. When not resisting foreign invaders, they battled one another or kept alive their fighting traditions in bitter blood feuds. The mountainous terrain of their peninsula, with few good roads or rail lines, hampered the countermeasures of regular forces and made possible sustained guerrilla operations. ”
