D. Prussian Chancellor Otto von Bismarck intentionally started a war with Austria and won.
Bismarck is well known for the application of the Realpolitik, in that he started the war with Austria as he wanted its traditional influence out of the German states. Prussia won the Seven Weeks War in a tactical maneuver to create a new balance of power and challenge the former status quo.
Some years before the war with Austria took place, the German Chancellor had weakened Austria power sphere in Europe. He stroke just in time and won: Having built up alliances with other European states, he created the conditions were Prussia was to emerge the leader to the rest of the German states.
Otto, defeating the Austrian then deviated from the previous Metternich policy were Prussia was a minor associate member in the German States Confederation having the strong cooperation with Austria. Prussia then served as the model for the building of a country that came late to European affairs and previously conditioned for unification were constrained by external actors. This state soon began to reshape European power dynamics.
