The World War 1 conflict began in 1914 to 1918. It started as a nearby European war between Austria-Hungary and Serbia on July 28th 1914. It transformed into a general European struggle by declaration of the following nations known as the 'Allies' and the 'Associated Powers'; Great britain, France, Russia, Italy and the United states. These nations defied the coalition(central powers). The assassination at Sarajevo in bosnia immediately caused the war between Austria-Hungary and Serbia on June 28th 1914.
The Triple Entente was involved in the first world war along with the Triple Alliance. The Triple alliance was formed by Germany, Austria-Hungary and Italy in 1882. These Countries agreed to assist each other if attacked by either France or Russia. In WW1, Germany attacked France which caused the Triple alliance to support them in there war.
Russia, who feared the growth in the German army, joined up with Britain and France which eventually formed the Triple Entente. The Russian Government was also very cautious and concerned about the possibility of Austria-Hungary increasing the size of their army's population.
One of the causes of World War was that they made all the aforementioned items join in the war (alliances, imperialism, militarism, nationalism) and then was the assassination of Archduke Franz Ferdinand of Austria-Hungary. In June 1914, him and his wife were assassinated by a Serbian Nationalist while they were in Sarajevo, Bosnia which was part of Austria-Hungary. Austria-Hungary was in protest of having control of this region. Serbia wanted Herzegovina and Bosnia to belong to them. This assassination led to Serbia being declared of war by Austria-Hungary. When Russia began to mobilize because of its alliance with Serbia, Germany quickly declared war on Russia. This expanded the war including all those involved in the mutual defense alliances.
Another cause was Nationalism.Bosnia and Herzegovina no longer wanted to be part