1. Rivalry and Competition: Leading up to World War I, there were tensions between major European powers, particularly between Austria-Hungary, Germany, France, and Russia. Each country was vying for greater power, prestige, and influence in Europe and beyond. These rivalries and competition created an atmosphere of distrust and insecurity among these nations and made them more susceptible to conflict.
2. Nationalism: Nationalism was a powerful force in Europe during the late 19th and early 20th centuries. Each nation had its own aspirations and sense of national pride, which could lead to conflicts with neighboring countries. The annexation of Bosnia and Herzegovina by Austria-Hungary in 1908 had already heightened tensions with Serbia, which saw the move as a threat to its own national ambitions in the region.
3. System of Alliances: Europe was divided into a complex system of alliances, whereby countries had mutual defense agreements with each other. These alliances were designed to maintain a balance of power in the region, but they also made it difficult for countries to remain neutral in times of crisis. When Austria-Hungary declared war on Serbia, its ally Germany was obligated to support it, while Russia, in turn, was bound to support Serbia.
4. Miscommunication and Diplomatic Failures: The days following the assassination were filled with confusion, miscommunication, and diplomatic blunders. Ultimatums, mobilizations, and diplomatic initiatives were exchanged among the major powers, leading to a breakdown in communication and a lack of understanding of each other's intentions. These failures contributed to the growing tension and the rapid escalation of the crisis.
5. Escalating Military Plans and Mobilizations: Once tensions began to rise, each country initiated its military plans for mobilization. As Austria-Hungary and Russia ordered their armies to mobilize, so did Germany and France, creating a sense of urgency and fear that war was imminent. The speed at which these mobilizations occurred limited the opportunities for diplomatic resolution and contributed to the outbreak of war.
In summary, the assassination of Archduke Franz Ferdinand was the catalyst that ignited already existing tensions and rivalries among major European powers. It set in motion a chain of events, compounded by nationalism, alliances, miscommunication, and military preparations, that ultimately led to the outbreak of World War I.