The pre-war alliance system in Europe was a major determining factor for the major power’s entering the war. Before the war, alliances were entered into as defensive agreements only. In October 1879 the Austria-Hungary Empire and Germany formed a formal alliance binding the two parties to assist each other, if either was attacked by Russia or another power. Three years later in 1882, Italy joined this alliance creating the ‘Triple Alliance. As a result of the Triple Alliance and Germany’s attempts at becoming a major world power, France, Russia And Britain worked together to form their own alliance system. France and Russia entered into a formal alliance in 1892 that stipulated that if Germany, or Italy supported by Germany, attacked either nation; the other would employ all of their available forces to attack Germany. While Britain had agreed to an alliance with France and Russia, forming the Triple Entente, it would not formally commit to a full military alliance naming Germany as the enemy. Britain did however, commit to an obligation to protect Belgium and her sovereignty. As war broke out and Germany invaded Belgium after implementing the Schlieffen plan, Britain was forced to join the Entente and declare was on Germany.