“Most of the leaders in 1914 had no real idea of the war machine they were putting into motion. Many believed the War would be over by Christmas 1914. But by the end of the first year, a new kind of war emerged on the battlefield that had never been seen before -- or repeated since: total war-producing stalemate, the result of a war that went on for 1,500 days." The above quote would be directly related to which of the following causes of WWI?
Warfare had changed, gas , planes , later on tanks in 1916 machine guns and old tactics was outdated, charging horses into machine guns, isn't a good idea.
