Nationalism and militarism were big reasons why World War I started. These factors led to a huge conflict that involved many countries and caused unimaginable loss of life and resources.

Nationalism:

• Nationalism made countries in Europe compete fiercely with each other. People wanted their nation to be proud and powerful, so they often put their own interests before talking things out peacefully.
• A key moment was when a nationalist group in Serbia assassinated Archduke Franz Ferdinand of Austria-Hungary on June 28, 1914. This event raised nationalist feelings, especially in the Balkans, where different ethnic groups wanted their own independence or more land.
• In Germany, nationalism was also strong. The population grew from about 41 million in 1871 to over 67 million by 1914, which was more than a 60% increase. This growth fueled the desire for a larger empire.

Militarism:

• Militarism was another important factor as countries built up their armies and navies. By the early 1900s, European nations were competing in an arms race. Between 1900 and 1914, military spending went way up:
  • Germany: Increased from $94 million in 1900 to$350 million in 1914.
  • Britain: Grew from $155 million in 1900 to$225 million in 1914.
  • France: Jumped from $96 million in 1900 to$300 million in 1914.
• Many people believed that military action was the answer to political problems, which led to a culture that celebrated war. Military leaders had a lot of power and could influence government decisions.
• The different alliances that formed, based on mutual protection and military strength, also made things more complicated. For example, the Triple Alliance included Germany, Austria-Hungary, and Italy, while the Triple Entente included France, Russia, and Britain. These alliances created a complex network that made the situation more explosive.

In short, nationalism and militarism created a perfect storm for conflict, leading to World War I. The war resulted in around 16 million deaths and changed the world map, influencing international relationships for many years afterward.