For the past two weeks, observers of North Korea's strange and tightly restricted corner of the internet began to notice that the country seemed to be dealing with some serious connectivity problems. On several different days, practically all of its websites—the notoriously isolated nation only has a few dozen—intermittently dropped offline en masse, from the booking site for its Air Koryo airline to Naenara, a page that serves as the official portal for dictator Kim Jong-un's government. At lea...