This country united under the manipulations of a politician who believed in Realpolitik. First, this Junker organized and trained an army, vastly improving it. Then, his country allied with Austria to attack Denmark to seize land. After Denmark's defeat, this country turned on its former ally Austria, and seized more land, as well as forcing Austria to stay out of the affairs of this nation. Finally, to unite the northern and southern provinces of this country, the Junker created a nationalist dispute with France. This war with France was the catalyst that united the country. What country does this passage refer to