There were many reasons why World War One broke out: imperialism was taken into effect, nationalism and unification of nations was very popular, alliances all over Europe were established and glorifying one’s military rapidly rose. World War One started in July of 1914, and lasted until November 1918. The primary cause of WW1 was the assassination of Archduke Franz Ferdinand; however, alliances developed prior to the war and the glorification in country’s military made the call for war nearly imperative.Militarism is when a country builds a strong military with the intention to use it when it is thought necessary.A nation will glorify it’s military and impose a threat to surrounding nations, which will lead those nations to establish larger, stronger, and more potent militaries. This was the case with Germany and France: Germany began to build up a forceful army in order to prepare for defense against France if necessary. This made the French feel threatened, and influenced to initiate in building an even larger army.This caused WW1 because both nations felt a threat against each other.The main cause of WW1 was the attack against Franz Ferdinand, who was the heir to the throne of the Austro-Hungarian Empire. Austria-Hungary had control over Serbia, and Serbs did not like this.The Black Hand, a Serbian terrorist group, wanted Serbia to be free from Austria-Hungary’s rule. This caused WW1 because the nationalism in the Black Hand drove them to attack Ferdinand in order to try and gain back Serbia’s control in its land. The goal of the Black Hand was to break of Austro-Hungarian power in Serbia to form a Greater Serbia, which would be accomplished by attacking Ferdinand in Sarajevo, Bosnia where he was scheduled to visit on June 28, 1914. This assassination led Austria-Hungary to believe Serbia was behind the BlackHand’s movement. After the assassination of Franz Ferdinand, Austria-Hungary declared war on Serbia. As Serbia and Austria-Hungary prepared to go to war, Russia offered support to Serbia, causing for Germany to declare war on Russia. This caused WW1 because the alliances drew nations into fighting, and it led to a huge war. As Germany and Russia went to war, Russia looked to France for help. Germany later declared war on France due to its alliance with Russia, and soon, Germany invaded Belgium as part of the Schleifen Plan.The Schleifen Plan was arranged for Germans to invade Belgium, and through Belgium, take Paris, then sweep back to Russia to take Moscow. This caused WW1 because the powerful nations of Europe were drawn into a state of war, and after Germany’s invasion in Belgium, Great Britain (who was allied with Russia and France) declared war on Germany and began a naval blockade (didn’t allow for Germany to get supplies). The primary cause of WW1 was the assassination of Archduke Franz Ferdinand; however, alliances developed prior to the war and the glorification in country’s military made the call for war nearly imperative.The assassination brought attention to many nations, which led to a rise in militarism between nations. Alliances also led to many nations coming together, using their militaries to take down opposing nations. Irrelevant things like feeling your army and navy is stronger than that of some other nations, connection between countries, and the attacking of an unpopular Austro-Hungarian heir led to a breakout of chaos in what we know today as World War One.