The Triple Alliance was a major cause of the First World War. The war began in 1914 when Austria-Hungary declared war on Serbia after the assassination of Archduke Franz Ferdinand. Russia, which was allied with Serbia, began to mobilize its troops in response to Austria-Hungary's declaration of war. Germany, which was allied with Austria-Hungary, responded to Russia's mobilization by declaring war on Russia and France, which was allied with Russia. This quickly led to a world war, as the other major European powers were drawn into the conflict.
The risk of Triple Aliance was that it could lead to a world war. This risk became a reality in 1914 when the assassination of Archduke Franz Ferdinand sparked a chain of events that led to the First World War.