In World War I, the Allies, which included France, Britain, Russia, Italy, and the United States, fought the Central Powers, which included Germany, Austria-Hungary, and the Ottoman Empire. The United States entered the war in l917. (Russia withdrew later that same year.)<NP> The war resulted chiefly from competition for colonial and economic power among European nations, the desire of national groups to gain independence, and secret military alliances among the nations of Europe. In the war, millions of men, women, and children were killed, and whole cities were destroyed. The Allies won the war in l9l8.<NP> After the war, Germany was forced to disarm, give up much of its territory, and pay war damages to the Allies. Austria-Hungary and the Ottoman Empire split into national states.
