Kammala jumla mai zuwa: Bayan "Anschluss" na Maris 1938, lokacin da Jamus ta haɗu da Austria, Yugoslavia ta zo ta raba iyakarta ta arewa maso yamma da Jamus kuma ta faɗa cikin matsin lamba yayin da maƙwabta suka haɗa kansu da ikon Axis. A watan Afrilu na shekara ta 1939, Italiya ta kai wa Albania hari kuma ta mallake ta, ta haka ne ta kafa iyaka ta biyu da Yugoslavia. A lokacin barkewar Yaƙin Duniya na II, Gwamnatin Sarautar Yugoslavia ta ayyana tsaka tsaki. Tsakanin Satumba da Nuwamba 1940, Hungary da Romania sun shiga Yarjejeniyar Tripartite, suna daidaita kansu da Axis, da Italiya
suka mamaye Girka. A lokacin, ƙasashen da ke ƙarƙashin ikon Axis da kuma ƙasashen da suke ƙarƙashin ikonsu sun kewaye Yugoslavia gabaki ɗaya, kuma matsayinta na tsaka tsaki game da yaƙin ya zama da wuya. A ƙarshen Fabrairu 1941, Bulgaria ta shiga cikin Yarjejeniyar. Kashegari, sojojin Jamus sun shiga Bulgaria daga Romania, suna rufe zoben da ke kewaye da Yugoslavia.