" vast and pivotal expanse of Central Asia and its Mongol-Turkic hordes. These four marginal regions, as he informs us, correspond not coincidentally to the four great numerical religions: for faith, too, in Mackinder’s judgment, is a function of geography. There are the “monsoon lands,” one in the east facing the Pacific Ocean, the home of Buddhism; the other in the south facing the Indian Ocean, the home of Hinduism. The third marginal region is Europe itself, watered by the Atlantic to the west, the hub of Christianity. But the most fragile of the four outliers is the Middle East, home of Islam, "

― Robert D. Kaplan , The Revenge Of Geography: What the Map Tells Us About Coming Conflicts and the Battle Against Fate