There were are number of interacting factors which were important. Among these were that Europe was divided into Armed Camps that each country was eagerly preparing to fight for the benefit of its own nation. In the years after 1900, many European people were aggressive nationalists. They thought that their own country was best. One of the forces making for trouble was extreme nationalism. This was a very powerful emotion. People who fell under this spell were willing to take any action to help their own nation, regardless of its effect on others. To promote their nationsâ€