In announcing that it will restart its nuclear facilities, North Korea seems to many people to be behaving strangely. In fact, North Korea is behaving predictably: it is issuing belligerent statements, cutting off hotlines and taking ever more threatening postures. The big question is: should the response of the world be equally predictable?

The US seems to think so. It refuses to talk directly to Pyongyang, preferring to continue with isolation and sanctions. This is the wrong approach. It is reasonable to fear that North Korea wants war. But its record shows that bellicosity is the only way it believes it can get attention. Maybe it is time to show North Korea that it does not have to behave weirdly to get talks going.

To understand why, let’s go back to basics. Diplomacy was invented thousands of years ago to enable us to talk to our enemies. It prevented envoys from having their heads chopped off at rival courts. Diplomacy was never primarily about communicating with friends.