Please tell us how Europe gradually became a powder keg according to the situation in Europe before World War I?

The Franco-Prussian War, World War I and World War II, the hegemonic shift of the European continent and the opposition of great powers directly led to the decline of modern European civilization! The rise of a great country is due to the decline of tragicomedy. After the Franco-Prussian War, France lost its hegemony in continental Europe. Bismarck, the winner, failed to maintain his usual self-control and balance, not only captured Alsace and Lorraine in France, but also insulted the Prussian emperor in the mirror hall of Versailles, France, which led to great hatred between France and Germany. The outbreak of World War I was the bitter fruit of hatred between France and Germany. The Franco-German diplomatic opposition before World War I, like two millstones, involved Russia, Austria-Hungary, Britain, Italy, Turkey, Serbia and the United States and suffered together. The confrontation between the two major political and military groups in Europe could not be eased, and eventually war broke out because of an accidental assassination in the Balkans.