World War I began on July, 28 1914. The main reasons for this was mutual defense alliances, countries throughout Europe made defense agreements that would pull them into battle. These agreements meant that if one country was attacked then allied countries would defend them. Austria-Hungary declared war on Serbia, Russia allied with Serbia. German declared war on Russia. During all this, France was against Germany and Austria-Hungary. Germany went to war with France in Belgium puling Britain into war, then Japan entered the War. Later, Italy and the United States went to war on the same side as the allies. There were many causes to World War I. Imperialism is when a country grows their power by adding territories that they can control.
