The conflict known for the phrase "the war to end all wars" is World War I. This term, popularized in the 1910s, reflects the widespread belief that the sheer scale and destructiveness of the war would prevent future global conflicts. The war involved many nations and resulted in profound changes in geopolitical boundaries and societies. It was characterized by trench warfare, immense loss of life, and innovations in military technology. Although the term implied a final resolution to global conflict, history proved otherwise, leading to World War II and continuous global tensions.