The phrase "the war to end all wars" refers to World War I, which lasted from 1914 to 1918. This expression was popularized by President Woodrow Wilson and was intended to convey the hope that the immense destruction and loss of life during the war would lead to lasting peace and prevent future conflicts. Sadly, the dream of a permanent peace did not materialize, as unresolved issues and grievances from the war contributed to the outbreak of World War II. The phrase encapsulates the disillusionment of the time and raises questions about the nature of warfare and its consequences.