Why did Otto von Bismarck see the Balkans as a danger to European peace?

Otto von Bismarck viewed the Balkans as a significant danger to European peace primarily because the region was the site of the Eastern Question—the diplomatic instability caused by the gradual disintegration of the Ottoman Empire.12

Bismarck feared that this political disarray would inevitably trigger a conflict between the Habsburg monarchy (Austria-Hungary) and Russia, both of which sought to expand their influence over the newly independent or feuding Balkan nationalities. He believed that such a clash could escalate into a general European conflagration that would force Germany to intervene, thereby threatening the stability and security of the German Empire.134

To mitigate this risk, Bismarck acted as an honest broker, such as at the Congress of Berlin in 1878, and utilized complex alliance systems—including the Dreikaiserbund and the Reinsurance Treaty—to neutralize regional tensions and prevent either Austria-Hungary or Russia from gaining a decisive, destabilizing advantage in the Balkans.135