North Korea has launched three intermediate range ballistic missiles in the last two weeks. Each one was a failure and ended in an explosion or crash. The UN Security Council has banned such tests and issued a warning about increasing sanctions if such misbehavior continues. Indeed, there might be worse trouble in store. Many expect North Korea to conduct another nuclear test, its fifth. On May 6 the country is holding the first congress of its ruling Workers’ Party in 36 years.