What was the final outcome of WWI?
All of the Central Powers were dismantled and reorganized.
The German Empire became the Weimar Republic, which was fairly democratic until the worldwide Great Depression steered it towards National Socialism. Germany assumed a crippling war debt, and the UK occupied Hannover for about a decade.
The Ottoman Empire broke up and its central holdings became the nation of Turkey. Many modern Middle Eastern nations were carved out of the remains. The Austro-Hungarian Empire broke up into Austria, Hungary and much of modern Eastern Europe.
Russia, because of the October Revolution at home, quit the war early and soon became the hub of the Soviet Union. America was in its early stages of the world's dominant military power.
Dada, an antiwar art movement created by draft resisters in Switzerland, evolved into Cubism. Expatriates who settled in Paris launched the Lost Generation literary movement. Jazz electrified musicians on at least two continents.
Airplanes went from wood-and-canvas oddities to sophisticated propeller-driven machines. Submarines and tanks became essential parts of every serious military endeavor. More men died from combat than from disease for the first time ever in war.