Germany's Role in World War One In the early 1900's, there was much stress in Europe. Imperial competition, a strong feeling of nationalism and the fear of war, caused countries to ally with one another. Also, fear of an arms race further increased this tension and contributed to the outburst of war. Although Germany could be held most responsible for causing World War One, she was not alone in setting the wheels of war in motion. Several countries had their own reasons for wanting battle. A Serbian terrorist group, The Black Hand, sparked the match to war by assassinating Archduke Francis Ferdinand of Austria-Hungary. In retaliation, Austria-Hungary