Answer
Halford Mackinder and Nicholas J. Spykman were major influencers of Zbigniew Brzezinski's geopolitical traditions. Mackinder argued that the Eurasian landmass was the key to global power, and that the country that controlled this region would dominate the world. Spykman agreed with Mackinder's assessment, but he argued that the United States was best positioned to control Eurasia because of its geographic position and its economic and military power.