Why was the Balkan Peninsula in Europe regarded by many as a powder keg prior to
the Great war?

Answer:
29.2. 3: The Balkan Powder Keg. The continuing collapse of the Ottoman Empire coincided with the rise of nationalism in the Balkans, which led to increased tensions and conflicts in the region. This “powder keg” was thus a major catalyst for the outbreak of World War I.
Explanation:Hopefully this helps!