First as a colony, and then as a divided country, Korea became a site, and subsequently a highly unlikely fulcrum, for the transformation of the international system —from one of rapidly declining British leadership in the early 1930s, to a short period of regional Japanese hegemony in East and Southeast Asia, thence to a defining crisis in 1950-51 that became the global building block for American global predominance. Korea was Japan’s most important colony and, later, a model for Manchukuo, and was the centerpiece of its regional strategy of political economy in the interwar period. Later on, the Korean conflict ushered in a transformation of American power in the world, and in the 1960s the Republic of Korea (ROK) became a key model for American-promoted export-led development as the remedy for underdevelopment in the “third world.”