Discipline: Political Science
Theory of geopolitics described by the British geographer Sir Halford Mackinder (1861-1947).
The group or nation which dominates the 'heartland' can then extend its domination over a far wider area. This heartland has at various times been Central Asia, the high seas, and Eurasia.
Graham Evans and Jeffrey Newnham, The Dictionary of World Politics (Hemel Hempstead, 1990)