Answer:
The start of WWI could not have been avoided.
At that time period (1914), all of Europe except for Switzerland and France were rule by Kings and Queens known as royal families. The general belief was these families were part of a higher class. They married within their class and in many cases, the rulers were related by blood. In effect they were ordained by God to rule their people.
Besides being the rulers of their countries, they were very wealthy. At the time there were a complex set of alliances where if one kingdom was attacked, its allies would rush to its aid.
The various royal families believed in having a strong military. The military served two purposes. First, would be as a strong defense and second would be as a supreme powerful offensive force.