In early October 1942, the division commenced Operation Kopaonik, targeting the Chetnik force of Major Dragutin Keserović in the Kopaonik Mountains. The operation ended with little success, since the Chetniks had forewarning of the operation and were able to avoid contact. After a quiet winter, in January 1943 Phleps deployed the division to the Independent State of Croatia (NDH) to participate in Case White. Between 13 February and 9 March 1943 he was responsible for the initial aspects of raising the 13th Waffen Mountain Division of the SS "Handschar" (1st Croatian) in the NDH in addition to his duties commanding the 7th SS Division.