Why was Balkan cooperation difficult before World War I?

Before World War I, cooperation among Balkan states was difficult due to a combination of competing territorial ambitions, ethnic complexities, and the influence of external powers.

• Conflicting Territorial Claims: The newly independent Balkan states emerged at different times and held overlapping claims to territory based on ethnic or historical rights. These competing interests made the concept of a lasting Balkan union rare and transitory.1
• The Macedonian Question: A primary source of friction was the inability of states like Serbia, Bulgaria, and Greece to agree on the division of Macedonia. While they briefly united in the Balkan League to defeat the Ottoman Empire in 1912, this cooperation quickly collapsed into the Second Balkan War in 1913 over the partitioning of their conquests.12
• Ethnic and Economic Disruptions: The creation of modern state boundaries often failed to align with ethnic divisions, creating persistent minority problems. Furthermore, these new borders frequently interrupted established economic patterns, such as traditional trade routes and seasonal migration for shepherds, which hindered regional integration.1
• External Influence: The region was subject to the interests of great powers, such as Austria-Hungary and Russia, whose shifting alliances and interventions often exacerbated local tensions rather than fostering stability.23