What happened to the alliances after archduke franz Ferdinand was assassinated?

After the assassination of Archduke Franz Ferdinand in June 1914, the complex system of alliances in Europe rapidly escalated tensions into World War I. Austria-Hungary, backed by Germany, issued an ultimatum to Serbia, which was supported by Russia. This triggered a chain reaction, leading to Germany's declaration of war on Russia and then on France, while Britain entered the war following Germany's invasion of Belgium. The alliances that were meant to provide security instead contributed to a widespread and devastating conflict.