The alliance system did cause the size of the war as it caused countries to be pulled in. First made in the Franco- Prussian war. Alliances held countries to some sort of standard and normally required something of each participant. The triple alliance signed by Germany, Austria-Hungary and Italy bound each country to give military support in a case of war or "if any one member of the alliance was at war with any two great powers other members would come to aid". When the entente was made it did not intend for reciprocal arrangements for support, though it did allow wide variety of arrangements negotiations to take place, one negotiation would have been of support in war. But by 1911 A.J.P Taylor said "the entente was in the process of disintegration." and was not seen as strong, because of the triple alliance Germany came to Austria's aid willingly, which plunged Germany into war. When Germany declared war on France and Russia, Austria- Hungary was pulled into that battle to fulfill their part of the alliance. This had four major powers fighting. Alliances pulled countries into war because if they were not followed a threat of retaliation would be expected.
On the other hand.
Other causes include Nationalists wanting freedom, causing the Slavs to ultimately assassinate the duke and causing hate towards to Austrian empire. Nationalism was also a major cause of war, it caused problems especially in Austria- Hungary and France. This same nationalism had brought Germany together a one country and who took Alsace- Lorraine from the French in 1870- 1871 in the Franco- Prussian war, and in recent times the Moroccan crisis which left the French with hatred as an attitude towards the Germans, the thought of revenge was also one that was favored by the French nationalists. While this unrest was happening in France, nationalism was also causing problems in the areas of Austria- Hungary, over here the nationalists were slavists who wanted freedom from the Austrian empire, they had been growing more and more restless with Russia encouraging these wants of Slavs freedom till all hell broke loose when a nationalist assassinated the arch-duke which opened the gates to world war 1.
The assassination of the archduke marked the start of the war, this did not involve any alliance just hate and oppression of the Slavs. The assassination of the archduke Franz Ferdinand began the unfolding of the events that led to war. Gavrilo Princip wanted to free Slavic people from the clutches of the Habsburgs he shot the arch duke and his wife in Bosnia while on tour. Austria issued a ultimatum about a month later, which Serbia refused to comply by thus starting a war between Austria and Serbia. Germany agreeing to support Austria because she was eager to apply her influence on the Balkan states and to keep Russia from gaining any more. If Austria won which was counted on and forseen, Germany would have more power and control in these states. Russia was on the side of Serbia and encouraged them to fight knowing that France would come to their aid if help was needed. Thus when Austria declared war on Serbia, Russia mobilized which caused Germany to declare war on Russia. France mobilized on the side of Russia, Germany decided to declare war on France which put the Schlieffen plan in action causing Britain to declare war on Germany because of the invasion of Belgium. The assassination did not occur because of an alliance or treaty, nor did the war with Serbia occur because of an alliance which plunged all of Europe into a war. Gavrilo Princip known to...