NORTH KOREA refuses to be bound by any global rules. Its hereditary dictator, Kim Jong Un, imposes forced labour on hundreds of thousands of his people and threatens to drench Seoul, the South’s capital, in “a sea of fire”. Nuclear weapons are central to his regime’s identity and survival. It has always been tempting for America and other countries to put North Korea’s nuclear ambitions on the back burner, in large part because of a chronic absence of good options for dealing with them. The history of unsuccessful responses to North Korea’s nuclear ambitions began in 1993, when Mr Kim’s father, Kim Jong Il, threatened to pull out of the nuclear Non-Proliferation Treaty (NPT) (see timeline above). So when in 2010 President Barack Obama made an impassioned plea for a world without nuclear weapons, there were grounds for optimism. Although Mr Obama has made progress in many areas, from non-proliferation deals with Russia and Iran, to international summits on nuclear security, his failure to stifle North Korea is glaring.