Following the assassination of Francis Ferdinand, all of the "Big 5" European countries were plunged into The Great War because of the intricate alliances set up by Otto Von Bismarck and other European political leaders. As the landscape of the war began to take shape, Germany set its Von Schlieffen Plan into motion. To eliminate the possibility of a two front war, the Von Schlieffen Plan stated that the Germany must swing through Belgium, and knock France out of the war before Russia even has a chance to mobilize. Since the early 20th century was a time of high nationalism, all countries thought that they had the technology and firepower to win the war easily; Germany was no exception. After overpowering Belgium, Germany met harsh resistance from the French. With this development came the understanding that these new technologies could be used just a well for defense as they could be for offense.
This stalemate on the western front caused the both the Germans and the French to dig a vast trench system from the Swiss Frontier to the English Channel, each side hoping to gain an advantage. The trenches consisted of bunkers, communication posts, machine guns, and the trenches themselves. Millions of soldiers lived and died in the trenches. Also living with the soldiers in the trenches were large rats and lice. The conditions in the trenches were horrible due to a combination of factors including enemy fire, rotting corpses, an intense stench, and numerous diseases associated with trench life, such trench foot. This new type of trench-based warfare may have played a significant part in the war's casualties; ten to thirteen million people died and another thirty million were wounded in this war.
Bull, Stephen. World War I Trench Warfare (I) 1914-16. New York: Osprey...