In World War I, the neutral countries were Argentina, Chile, Denmark, the Netherlands, Norway, Spain, Venezuela, Sweden and Switzerland. These were the only 10 countries that were able to remain neutral throughout World War I.
World War I, also known as the Great War, took place from 1914 to 1918. The Central Powers of Germany, Austria-Hungary, and the Ottoman Empire fought against the Allied Forces of Great Britain, the United States, Russia, Italy, France, and Japan. World War I is particularly well known for its introduction to modern technology that led in an unbelievable amount of damage, with 9 million soldiers killed by the end of the war. The war officially ended in November 1918.
World War I began with the assassination of Archduke Franz Ferdinand and his wife on June 28th, 1914. The couple was the heir to the throne of the Austro-Hungarian Empire. On July 28th, 1914 the Emperor of Austria-Hungary, Emperor Franz Joseph, declared war on Serbia. Russia announced a full mobilization of the Russian armed forces just three days later as an ally of Serbia. The next day, Germany mobilized their armed forces with a declaration of war on Russia. Two days later Germany declared war on France. The escalation continued until all of the World Powers besides the ten neutral countries were forced to pick sides.