To what extent, Germany was responsible for the outbreak of the First World War?

After the Franco-Prussian war 1871, Germany kept France isolated as Bismarck formed a system of military alliance that did not allow France to form any alliances. But, the mismanagement of alliances initiated formation of counter alliances the Europe got divided into two hostile armed camps, Germany, Austria and Italy on one side and France, Britain and Russia on other side.
The colonial rivalries which resulted in Moroccan Crises in 1906 & 1911. The Germans accused France, Britain and Russia that they are encircling it and was not satisfied with the large colonial empires of France, Britain and Russia.
The arms race which was mainly going on between Germany and Britain, both were engaged in expanding their naval power created hostile environment.
The tragedy of miscalculation played a great role in outbreak of World War I. Austria Declared war on Serbia because of unconditional support from Germany. But miscalculated that Russia will not support Serbia. When Germany tried to confront France going through Belgium, but Belgium being neutral nation and the promise of Britain to save Belgium from any aggression led to the entry of Britain into the war. The miscalculation of the mobilisation of Germany and Russia that it would not result in war. Because of this dichotomy, every European nation was busy in arms race to face any attack. This approach resulted in immense military infrastructure and led to outbreak of the war eventually. So Germany, Austria and Russia must share the responsibility of World War I.