After Japan surrendered in '45 and ended its occupation of Korea, the US and USSR divided the peninsula and set up puppet regimes. The US never thought South Korea was important, withdrew American troops in '48, and in January 1950, Secretary of State Dean Acheson told the National Press Club that the US "defense perimeter" in Asia didn't include South Korea. Six months later, North Korea, with Soviet (and later Chinese) support, invaded the South. Truman had no policy vis-a-vis South Korea, and the US was forced to fight that war virtually alone, with just a skimpy loincloth of UN diplomatic support. Result was a bloody stalemate.