North Korea leader Kim Jong Un's No. 1 objective is surely the survival of his regime, and of himself as leader, preferably for several decades, given his youth. It is less clear how he can best achieve this. Outright collapse of the North Korean economy and mass starvation, or nuclear war with the United States are both bad outcomes from his point of view, because both would destabilize or end his regime.
Complete stasis is the alternative chosen since the 1950s by his father and grandfather. This keeps the North Korean people poor, but mostly not in crisis, while the U.S. and the West make no significant attempts to dislodge him.
At first sight, the ideal role model for a North Korean opening is Vietnam. That country is extremely open to foreign investment, at least by major corporations, and has a functioning stock market with several domestic corporations listed on it, although the largest companies are majority government controlled. However, Vietnam relies heavily on foreign investment, most of which is for production exported to rich-country markets. As a result, Vietnam is an exceptionally open economy, with exports amounting to almost 100 percent of GDP.