Europe in the early 20th century was on the verge of war for many years. If not for Germany, this tension in Europe would have never been built up. Germany started building up this tension in the 1870's by instituting the Bismarcekian system. They first realized that war was inevitable and started pushing countries politically, militaristically, and economically into war. Because of these efforts, the world went to war, and in the end Germany was made to pay for its mistakes.
Moltke, the chief of the German General Staff, was preparing for the war as early as 1909. He had been waiting for a Serbian move against Austria-Hungary. He and, "a handful of men in Berlin had foreseen [the war] - and in a large part had planned it - long before." (Fromkin) When the time came, they urged Austria-Hungary to attack Serbia. They openly could not tell Austria to attack Serbia, for then they would lose the consent of the people.
Germany was preparing for this war even before it began. All they were waiting for from 1912 was for naval preparations to be complete.
The navy, once completed, was one of the driving militaristic forces that brought great powers such as Britain into the war. Germany was waiting on its navy to make sure that they stood a fighting chance. England however saw those ships as a threat. The German navy jeopardized England's economic trade. All their food was imported for they were very industrialized. The final straw was drawn when Germany invaded Belgium to gain access into France through the von Shlieffen plan. England was required to attack Germany, even though they were already provoked by the German navy.
Nationalism also played a part in provoking other countries. Each country's people viewed their country as...