Why did nationalist tensions emerge in the Balkans?

The Balkans was a region of geographical and ethnic variation comprising modern-day Romania, Bulgaria, Albania, Greece, Macedonia, Croatia, Bosnia-Herzegovina, Slovenia, Serbia and Montenegro whose inhabitants were broadly known as the Slavs. The nationalist tensions emerge in the Balkans because:

1. A large part of the Balkans was under the control of the Ottoman Empire.
2. The spread of the ideas of romantic nationalism in the Balkans together with the disintegration of the Ottoman Empire made this region very explosive.
3. The Balkan peoples based their claims for independence or political rights on nationality and used history to prove that they had once been independent but had subsequently been subjugated by foreign powers.
4. The Balkan states were fiercely jealous of each other and each hoped to gain more territory at the expense of the others.
5. There was intense rivalry among the European powers over trade and colonies as well as naval and military might. These rivalries were very evident in the way the Balkan problem unfolded. Each power – Russia, Germany, England, Austro-Hungary – was keen on countering the hold of other powers over the Balkans, and extending its own control over the area.