Reviews the strategic geography of the sea lanes from Northeast Asia through the Indian Ocean to Europe since the Middle Ages, noting how changing technology and economic patterns have transformed the global significance of those passage ways, especially since the end of the Cold War. The author, previously served as Special Advisor to the US Ambassador to Japan, is the recipient of major awards, including Japan's Order of the Rising Sun, the Arisawa and Ohira Prizes in East Asian Studies, and a Financial Times Book of the Year award.