Following the brutal Second Balkan War, in which Bulgaria's neighbors turned on it after its earlier victory over the Ottomans, diplomats hammered out fresh territorial arrangements in the Balkans. The settlements redrew borders in ways that left grievances festering, contributing to the combustible atmosphere that would help ignite the First World War less than a year later.
The Balkan Wars of 1912-13 are often overshadowed by the global conflict that followed them, but they were savage in their own right, marked by ethnic cleansing, forced population exchanges, and the collapse of centuries of Ottoman rule in Europe. Bulgaria, having done much of the fighting against the Ottomans, found itself attacked by former allies Serbia, Greece, Romania, and Montenegro, who feared its growing power.
The resulting peace settlements, including the Romanian-Bulgarian arrangements finalized in this period, stripped Bulgaria of territory it considered rightfully its own, particularly in Macedonia and the Southern Dobruja region ceded to Romania. Bulgarian nationalists never accepted these losses as final.
The bitterness lingered for decades. Bulgaria allied with the Central Powers in World War I largely to reverse the verdict of 1913, and Balkan territorial disputes from this era echoed through the twentieth century, resurfacing in the wars that accompanied Yugoslavia's breakup in the 1990s.