Geopolitics is the study of the effects of geography on international politics and relations. It emphasizes on the national security during a wartime period that could affect the international relationships and foreign policies. This term is becoming more popular in the twenty-first century because it has become the primary philosophy of the modern politics and economics interests of building a strong nation. It is also the modern philosophical term for mercantilism and imperialism, especially when it applies to American foreign policy along with many other powerful nations.