1. Imperial Rivalry and Alliance Systems:
- European powers were competing for colonies and influence in Africa, Asia, and the Middle East.
- Alliances had formed between major European countries, creating a system of rival blocs: the Triple Alliance (Germany, Austria-Hungary, and Italy) versus the Triple Entente (Britain, France, and Russia).
2. Nationalism:
- Growing nationalist sentiments and territorial disputes contributed to tensions between countries.
- Ethnic and cultural differences fueled desires for self-determination and independence, leading to conflicts in the Balkans and elsewhere.
3. Militarism:
- European countries had been engaged in an arms race, building up their military capabilities.
- Germany's rapidly expanding military, in particular, alarmed other powers.
4. The Assassination of Archduke Franz Ferdinand:
- The assassination of Archduke Franz Ferdinand, the heir to the Austro-Hungarian throne, on June 28, 1914, served as the immediate trigger for the war.
- Austria-Hungary issued an ultimatum to Serbia, which was backed by Germany. Serbia's partial acceptance led to Austria-Hungary declaring war on Serbia on July 28, 1914.
5. Chain Reaction of Alliances:
- Russia, allied with Serbia, began mobilizing its army in support of Serbia.
- Germany, in turn, mobilized its forces and invaded neutral Belgium, which was in violation of international treaties.
- France and Britain declared war on Germany in response to the invasion of Belgium.
The combination of these factors created a highly combustible situation in Europe, leading to the outbreak of World War I, which lasted from 1914 to 1918 and claimed the lives of millions of people.