Internal instability and international confusion determined Yugoslav's approach to the events that led to war in September 1939. The Regency headed by Prince Paul Karadjordjević endeavoured to solve numerous problems, internal as well as external, in order to maintain Yugoslavia in the constantly deteriorating international situation. A pronounced anglophile, Prince Paul had to hide his innermost feelings and adjust his policies to ever-changing realities. The feelings within the country were also deeply divided: the Croats looked to Italy and Germany for support, while the Serbs expected help from Great Britain and France. Besides the Croatian demands, which in essence amounted to the granting of complete autonomy, the Regency had to cope with an economic crisis, a dearth of capital, rivalry between Germany and Great Britain for control over Yugoslavia's mineral resources, problems of rearmament, as well as others.

It was Italy that initially posed the greatest threat to Yugoslavia, since Rome claimed the Balkans, especially the Adriatic, as her zone of special interest. The Fascist government had persistently tried to destabilise Yugoslavia by protecting extreme Ustashi elements and supporting Croatian separatism. The Italians also demanded the demilitarisation of the Dalmatian coastline, encouraged Hungarian revisionism, and finally attacked Yugoslavia's southern neighbour, Albania, and her ally, Greece. Belgrade blamed Italy and the Ustashi for the assassination of King Alexander in Marseilles in October 1934, and there is evidence to suggest that their suspicions were not misplaced. Soon afterwards however, the pro-Fascist prime minister, Milan Stoyadinović, set out to woo Italian sympathies.