Commonly Believed Cause of WW1
Strong feelings of nationalism throughout Europe prior to The Great War created an atmosphere in Europe which made war a likelihood. The spark which ignited the flame and transformed these underlying problems into a frenzy of hostilities happened on June 28, 1914, when Archduke Francis Ferdinand of Austria was assassinated by a Serbian student, Gavrilo Princip, while visiting Serbia.
The Real Cause of WW1
According to Albert Pike, the First World War was designed to enable the Czarist Government in Russia to be finally and completely overthrown and replaced with a new atheist, Communist government.
History records that this First World War did indeed occur as predicted. The Western powers in Europe, in conjunction with the United States, financed Lenin's expedition into Russia, and financed his government consistently. The US has financed Russian Communism at least once per decade since then.
A little closer to home:
In 1909, the Carnegie Endowment for International Peace was tasked to answer the following question posed by the US government: "If it is desirable to alter the lives of an entire nation, is there any means more efficient than war?" After a year of research, the answer came back: "There are no known means more efficient than war, assuming the objective is altering the life of an entire nation."
And for what reason would anyone want to alter the lives of an entire nation?
Historian Walter Mills wrote the following about the purpose of the war and about Colonel House's basic intent: "The Colonel's sole justification for preparing such a batch of blood for his countrymen was his hope of establishing a new world order, [a world government] of peace and security...."