The three most significant causes that lead to the outbreak of WW1 were alliances, imperialism, and assassinations. The alliance system and imperialism were both long term causes. They both caused friction and competition between the powers of Europe as they fought to gain allies and land. The assassination of Archduke Ferdinand was a short-term cause that caused anger and arguments between countries, dragging their allies into conflict as well. These long and short-term factors were ultimately the most significant causes leading to the outbreak of WW1 in 1914.The main cause of WW1 was the alliance system between the European powers, which had been in existence for many years before WW1. The alliance system was created years before WW1 to keep the peace between European nations, making it a long-term cause. Ultimately, this system of alliances had the opposite effect creating friction between the opposing sides. In 1882 Germany, Italy, and Austria – Hungary formed the Triple Alliance. Following that Britain, France and Russia made up the Triple Entente in 1907 to counteract their opposition.These countries eventually promised to defend each other from the opposing alliance. Their theory was that no single country would go to war with another with the risk of its alliance joined the fight, quickly escalating into a huge conflict between countries. In addition to the main powers being pulled into war by its alliances, many other countries under their power automatically became part of an alliance. For example, many nations around the world were under Britain’s control such as India and Australia, which meant at any point they could be pulled into a fierce conflict in Europe.Another important factor that led to the outbreak of WW1 was imperialism; it determined how powerful a country was. Imperialism was a policy of expanding a country’s power by taking control of new territories. Since the 15th century, European powers such as Britain, Spain, and France had already colonized much of America, Australia, and some of Asia. European nations soon began to compete with each other, as they all wanted to be the most powerful. They started to compete with each other, as they wanted to have the most control over Africa, which historians now call ‘the scramble for Africa.’ Britain had the largest empire but France and Germany tried to compete. France already had a decent size empire. Whereas Germany had only been unified since 1871 and was still trying to catch up. Kaiser Wilhelm II, the ruler of Germany desperately tried to take over some French colonies in both 1905 and 1911 but failed, France resisted Germany’s attacks, with Britain’s help, elevating tension between European nations. These occurrences escalated friction in Europe leading up to the outbreak of war.The third most significant cause of World War I was the assassination of Archduke Franz Ferdinand and his wife, a short-term cause. This assassination was the final event that triggered World War I in 1914. In 1908, Bosnia-Herzegovina became part of Austria – Hungary. Many ethnic groups lived there, so Serb Nationalists became angry because they wanted independence. This led to Austria – Hungary sending the Arch Duke and his wife to try to charm Bosnia Herzegovina. However, the Serbs were not happy so they assassinated both the Archduke and his wife. Austria Hungary gave Serbia an ultimatum with 10 demands, but only nine were approved. Exactly one month after the Archduke’s death Austria – Hungary declared war on Serbia, triggering most of Europe into conflict. On August 1st, Germany declared war on Russia after they promised to help Serbia its ally. This also lead to Britain declaring war on Germany with help from Australia and on August 6th Austria – Hungary announced war on Russia. The assassination of Archduke Franz Ferdinand was ultimately the last event that triggered World War I.The three most significant causes of WW1 were alliances, imperialism and the assassination of Archduke Franz Ferdinand. Alliances were created to keep the peace but ended up splitting Europe into two opposing sides competing to be the more powerful. Imperialism also largely contributed, with each country in a race to claim the most territory. Finally came the assassination of the Archduke of Austria-Hungary that elevated all tension and friction between European nations. These three factors all greatly assisted in the outbreak of World War 1 in 1914.