North Korea is an impoverished, famine-ridden nation, but it is also a nuclear power whose dictator Kim Jong-un regularly threatens his neighbors and adversaries, the United States in particular, with destruction. Even though Kim and President Donald Trump's responses to him dominate the daily headlines, the idea that North Korea is a menace is not a new one. Indeed, ever since Korea was first divided at the end of World War II, the tension between its northern and southern halves has riveted...