Answer:
Crises over the Balkans were not new — they had been a semi-regular occurrence in European diplomacy since the Greek War of Independence in the 1820s began the slow process of eroding Ottoman control over the region.
Step-by-step explanation:
The resulting power vacuum encouraged Russia, Austria and other great powers to try to move in to fill it either by supporting the creation of new states like Serbia, Romania and Bulgaria or taking territory directly (such as Bosnia-Herzogovina, annexed by Austria-Hungary in 1908). But equally important was the need of the European great powers to try and stop each other from gaining too much influence or power in the region as the Ottomans withdrew. Balancing these two often conflicting goals required very delicate diplomacy and was not helped by the emergence of the new Balkan states, like Serbia and Bulgaria, which were quite capable of turning the tables on those powers who sought to manipulate them as regional clients.