Balkan nationalism was a major factor in the outbreak of World War I. It is one of the long-term causes that led European powers to declare war on each other. Although the war between Austria and Serbia was expected to be short, it culminated in a worldwide conflict that lasted four years. The idea of ​​Pan-Slavism was the result of Serbian nationalism and Serbia refused to be oppressed by Austria-Hungary. The Serbs demanded the right to self-government and a unified state. However, their neighbor Austria-Hungary wanted to become an imperial power and this implied territorial expansion. Historians have different opinions on this topic, and due to its complexity, it cannot be said that any of them is completely right. The Balkan countries posed a great threat to his foreign policy and this led to the culmination of their conflict and the outbreak of war. Although nationalism is important in understanding the outbreak of World War I, there are many underlying causes that together culminated in a global conflict. It is difficult to reach a definitive answer on the question regarding the extent of the importance of Balkan nationalism in the outbreak of the war because there are many different perspectives for understanding this question. Ruth Henig, for example, believes that Balkan nationalism was extremely important for the war and places blame for the outbreak of the war on Austria-Hungary. On the other hand John Leslie says that Germany is responsible: “Austria-Hungary can be held responsible for planning a local Austro-Serbian conflict, this was linked to its fears regarding Balkan nationalism, but Germany, which was not interested in this dispute, she deliberately used it as an opportunity to launch the European war that Austria-...... middle of paper ...... is responsible for and alone. It is descriptive and provides a lot of information but at the same time it is also analytical because it presents different aspects and primary sources of Serbian history. The parts of the book that concern the origins of the First World War and the Balkan crisis are focused on the conflict between Serbia and Austria-Hungary, therefore not all the origins of the war are analyzed, but the influence of Balkan nationalism is analyzed in depth for the outbreak and provides a wealth of evidence to support his arguments. The book compares and contrasts the political and cultural history of the Serbs and is credible and objective. Regarding World War I it also provides many primary sources and perspectives from different scholars. The book is authoritative and it is easy to see that Corovic is a recognized expert on the subject.