What is considered the main cause of World War I?

The main cause of World War I is identified as militarism, alliances, imperialism, and nationalism, often referred to collectively as the "MAIN" factors. This framework helps encapsulate the complex web of political tensions and rivalries that ultimately led to the outbreak of the war in 1914.

Militarism refers to the arms race and the glorification of military power, which created an environment where countries were prepared for war. The alliances, which included two major coalitions—the Allies and the Central Powers—meant that a conflict between two countries could quickly involve others. Imperialism, the competition for colonies and territories, heightened tensions as nations vied for dominance. Lastly, nationalism instilled a sense of pride and rivalry among nations, often pushing them toward conflict over nationalistic ambitions.

While the assassination of Archduke Ferdinand is a significant event that acted as a catalyst for the war, the underlying causes laid deep structural tensions that had developed over decades. This assassination triggered a series of alliances and mobilizations, but it was these broader factors that created the environment where such an event could lead to a full-scale war. Similarly, while colonial rivalry and economic depression contributed to the tensions, they are subsets of the larger framework encompassed by militar