“Koreans on either side of the dividing line . . . are brothers and sisters and cousins from the same heritage, and at the same time they are bitter enemies who have been waging fierce struggles against one another for half a century.” —Don Oberdorfer, author of The Two Koreas

The Korean peninsula—an area of eighty-five thousand square miles in northeast Asia jutting from China and abutting Japan—was a unified kingdom for thirteen hundred years. For the past half century, however, it has been a land divided. Korea’s partition was a product of externally imposed events, specifically the Cold War between the United States and the Soviet Union that dominated world affairs for much of the second half of the twentieth century. Although the Cold War ended with the Soviet Union’s dissolution in 1991, Korea has remained divided. Numerous observers have labeled...