"It is only those countries having adequate resources of men and materials which can exercise a direct influence on the peaceful organization of international society." Nicholas J. Spykman, The Geography of the Peace (1944) A multipolar world system creates both greater opportunity and greater incentive for middle powers to assert their interests and seek to influence global norms and developments. Middle powers will be courted by big powers, giving them more room to maneuver. They will be critical components of any balance of power in the international system. The Difficulty of Defining Middle Powers In international relations and geopolitics, the idea of middle powers is admittedly a bit fuzzy. At times, they are defined in a geographic sense, as countries caught physically between large powers — such as Poland between Germany and the Soviet Union, or Korea between China and imperial Japan.