1. Nationalism: Intense nationalism and competition among European powers, particularly Germany, France, Austria-Hungary, Italy, and Russia. Each country sought to increase its power and prestige and assert its national interests.
2. Imperialism: European powers engaged in intense competition for colonies and territories overseas, leading to conflicts and tensions between them.
3. Militarism: European countries engaged in a massive arms race and military buildup, creating an atmosphere of fear and suspicion among nations.
4. Balkan Tensions: The Balkans, a region in Southeastern Europe, was a hotbed of ethnic and political conflicts. The assassination of Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, by a Serbian nationalist in Sarajevo on June 28, 1914, served as the immediate trigger for the outbreak of war.
5. Alliance Systems: Complex and interlocking alliance systems existed among European powers. For instance, Germany had alliances with Austria-Hungary and Italy, while France, Britain, and Russia had their own agreements. These alliances made it difficult to resolve conflicts peacefully and led to a chain reaction of declarations of war once the conflict started.
6. Economic Competition: Economic competition and rivalry between European nations contributed to tensions and resentment, further fueling the conflict.
7. Political Instability: Political instability within several European countries, including the rise of militaristic and nationalist leaders, created an environment conducive to conflict.
The combination of these factors, including nationalism, imperialism, militarism, the Balkan tensions, alliance systems, economic competition, and political instability, culminated in the outbreak of World War I.