What were the main causes of World War I?

The main causes of World War I were militarism, alliances, imperialism, and nationalism, often summarised as MAIN.

Militarism played a significant role as European nations expanded their armies and navies, creating an arms race. Countries like Germany and Britain competed to have the most powerful military forces, which increased tensions and the likelihood of conflict. This build-up of military strength made war seem not only possible but inevitable.

Alliances between countries also contributed to the outbreak of war. Europe was divided into two main alliance systems: the Triple Entente, consisting of France, Russia, and Britain, and the Triple Alliance, made up of Germany, Austria-Hungary, and Italy. These alliances meant that any conflict involving one country could quickly involve others, turning a small dispute into a full-scale war.

Imperialism further heightened tensions as European powers competed for colonies and resources around the world. This competition often led to conflicts in distant parts of the globe, which then fed back into European rivalries. For example, the scramble for Africa and disputes in the Balkans created friction between the major powers.

Nationalism was another key factor, as various ethnic groups sought independence and nations pursued their own interests aggressively. In the Balkans, Slavic nationalism was particularly strong, with groups like the Serbs wanting to break free from Austro-Hungarian control. This nationalist fervour contributed to the assassination of Archduke Franz Ferdinand of Austria-Hungary in 1914, an event that directly triggered the war.

In summary, the combination of militarism, alliances, imperialism, and nationalism created a volatile environment in Europe. These factors intertwined, making a large-scale conflict almost unavoidable by the early 20th century.