The Battle of Stalingrad
Austria-hungary attacked Serbia
to build their military up and take control of England?
The United States was the nation that emerged from World War 1 as the greatest world power. By remaining neutral for most of the war and the land-lease act the United States was able to leave the war with more power than before.
Germany was forced to pay.
The u.s policy during the first world war was policy of isolation
Germany wanted to keep the United States out of the war, while Great Britain wanted the United States to join it.
They were both simply taken away by the Allies from their previous owners. Germany lost all its colonies; the Allies saw to it that the Ottoman Empire lost all its territories outside of the borders of today's Turkey.
Though huge numbers of people were killed, no country managed to conquer much territory