Final answer:
The Japanese adopted the idea of Realpolitik from Otto von Bismarck's German Empire.
Step-by-step explanation:
Otto von Bismarck, the architect of German unification, established the German Empire in 1871. As its first Chancellor, he skillfully used diplomacy and war to unify disparate German states under Prussian leadership. Bismarck's pragmatic policies aimed to strengthen and consolidate the new empire, shaping European geopolitics.
The Japanese adopted the idea of Realpolitik from Otto von Bismarck's German Empire. Realpolitik is a political philosophy that emphasizes practicality and realism in decision-making, rather than ideology or morality. Bismarck, as the Prime Minister of Prussia, employed Realpolitik to strengthen the military and expand Prussian power, and this idea influenced the Japanese as they sought to strengthen their own nation.