At first glance, the results of this week's Pyongyang summit can be divided into three categories. First, there are agreements and gestures which are largely or exclusively symbolic, and whose major goal is to maintain the spirit of optimism and the impression that progress is being made towards denuclearization. This impression is wrong, but both sides have good reason to heavily invest in keeping it alive.

Second, there are agreements (well, perhaps only one) which deal with important issues and are likely to make a difference.