ABSTRACT
This chapter explains how geopolitical theory developed and identifies its component parts. It provides an account of two of the most important classical geopolitical thinkers: Nicholas Spykman and Sir Halford Mackinder. The most important claim that geopolitical theory makes is the ability to explain historical change. Individual states can thus be seen as being the bricks, but it is the patterns and structures which they make in combination which are the principal interests of geopolitical investigation. The origin of geopolitical theory needs to be understood in terms of its specific historical context. The American Spykman was one of the most important geopolitical thinkers of the twentieth century. Spykman's ability to identify geographical patterns of political and strategic history and to imagine their geopolitical and geostrategic consequences in the future was the basis for a seminal policy recommendation to his adopted country. Mackinder was also aware of the subtle relationship between geography and human agency, specifically with respect to policy decisions.
