The optimism that followed the war led to international efforts to promote peace. One notable outcome was the establishment of the League of Nations, a global organisation designed to resolve conflicts through diplomacy and collective security. However, idealism waned as new conflicts emerged, including the rise of fascism and the outbreak of World War II two decades later. Despite the failure to achieve lasting peace, the phrase "war to end all wars" served as a potent reminder of the suffering caused by war and the aspiration to avoid future conflicts.