I agree with your statement that the assassination of Archduke Francis Ferdinand of Austria-Hungary was the trigger rather than the sole cause of World War I. It is true that there were several underlying causes that contributed to the outbreak of the war.
To delve further into this topic, it is important to understand the various causes that historians have identified. One major factor was the complex system of alliances and rivalries between different European powers, which led to a delicate balance of power. Additionally, there were growing tensions between major powers over issues such as territorial disputes and competition for resources and colonies.
Nationalistic aspirations and old prejudices also played a significant role, as you mentioned. The desire of different ethnic groups to assert their independence and self-determination fueled conflict in various regions. Furthermore, the rapid industrialization and militarization of many countries contributed to a sense of competition and increased the likelihood of conflict.
To gain a comprehensive understanding of the causes of World War I, researching reputable historical sources can provide more in-depth information.