1. Nationalism: The rise of nationalism and the desire for national self-determination contributed to tensions between European countries. Imperial rivalries and territorial disputes fueled competition and hostility.
2. Imperialism and Colonialism: The competition for resources, markets, and colonies among European powers created tensions and rivalries. The search for colonies and control over territories led to conflicts and heightened mutual suspicions.
3. Militarism: European countries engaged in an arms race and built up their military capabilities, leading to a climate of fear and distrust. Germany's growing military strength and its challenge to the established powers, such as Britain and France, increased tensions.
4. The Alliance System: A complex network of alliances formed between European countries. These alliances created a situation where a conflict between two countries could quickly escalate into a wider war involving multiple nations.
5. Assassination of Archduke Franz Ferdinand: The assassination of Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, on June 28, 1914, is considered the immediate trigger for World War I. The event sparked a series of diplomatic crises and ultimatums that ultimately led to the outbreak of hostilities.
It's important to note that the causes of World War I were complex and multifaceted. While these factors are often cited as contributing to the war's outbreak, their relative importance and interconnections are still debated among historians.