1.  What were the underlying causes of WWI?
First of all, aggressive nationalism was spreading throughout Europe. Nationalism was especially strong in France and Germany. Germans were proud of their military power and leadership, and France grew jealous, creating tension in Europe. Secondly, economic and imperial rivalries made countries suspicious of their neighbors. For example, England felt threatened by Germany’s rapid economic growth. Imperialism had also made quite a few enemies across Europe. Thirdly, the late 1800s saw a rise to militarism, the glorification of the military. Under militarism, the armed forces and readiness for war came to dominate national policy. Militarists painted war in romantic colors and brainwashed Europeans, making them believe that the dying for your country is the noblest way to die. Large alliances were being formed between the giants of Europe. The British felt threatened by Germany's economic growth.  The Germans were making more factories and out producing the old economic strong hold, Britain.  Imperialism divided the European nations and in the early 1099s the competition for colonies brought France and Germany to the prink of war.  Before the war the arms race began and all the great powers started building up their armies.

2.  What was the specific cause of WWI?
The specific cause of WWI was the assassination of Archduke Franz Ferdinand. When he was killed it was the straw that broke the camel's back so to speak.

3.  How did the soldiers react as they went off to war? Why?e
The soldiers going to war didn't know better. They thought that the war would only last a day and that it would be easy. They also thought that what they were doing was the only way to show their love for their country. If they stayed everyone would have thought that they were cowards.