Answer:
Nazi Germany
Step-by-step explanation:
Friedrich Ratzel was a famous German ethnographer and geographer. He is known for his famous Friedrich Ratzel theory. He developed the concept of 'Lebensraum' or 'living space'.
He was the first political geographer who studied the state in detail andf stated that state resembles a biological organism.
According to the Ratzel theory, Nazi Germany used the concept of geopolitics as a philosophy of expansion.
Thus the answer is Nazi Germany.