This single event led to the outbreak of WWI.

Question

Ideals of Social Darwinism

Military buildup of Germany

Assassination of Archduke Francis Ferdinand

Fear of another Napoleon

Answer 1

The single event that directly led to the outbreak of World War I was the assassination of Archduke Francis Ferdinand. On June 28, 1914, the heir to the Austro-Hungarian throne was assassinated in Sarajevo by Gavrilo Princip, a member of the nationalist group known as the Black Hand. This event set off a chain reaction of alliances and conflicts that ultimately led to the war. While the other factors you mentioned, such as Social Darwinism, the military buildup of Germany, and the fear of another Napoleon, contributed to the broader context of tension in Europe, the assassination was the immediate catalyst for the conflict.