Die Heartland-Theorie des britischen Geografen Halford J. Mackinder ist eines der bedeutendsten geostrategischen Konzepte, das kontinuierlich bis in die Gegenwart hinein als Erklärungsmuster herangezogen wird, um geopolitische Ambitionen einzelner Staaten oder Konflikte im globalen Kontext zu deuten.

The American public gives too much credit to what may be called, and what is called in Europe, our effort to guide the world aright. America’s great world political position is not due primarily to our moral leadership but primarily to our wealth and economic position. It is not to our moral teachings that the rest of the world responds, but to our material power. If we were a poor and weak nation the world would today care no more about what we thought than did the world before the Great War. [...]