Leaders of major oil-exporting countries used to talk about “saving the oil” for their grandchildren. But now the grandchildren are in charge, and they want to monetize the oil. That is certainly so in Saudi Arabia, where Deputy Crown Prince Mohammed bin Salman—a grandson of the country’s founder, Abdul Aziz ibn Saud—has launched an ambitious plan to reduce the country’s dependence on oil. Decrees issued this month announced far-reaching changes in Saudi ministers and government organization. Yet the result could end up making Saudi Arabia, which now produces one out of eight barrels of the world’s crude, an even bigger player in the global oil market. Prince Mohammed’s Vision 2030 plan comes as the oil market is working back toward balance, having crashed to a low of $26 a barrel in February from $100 in 2014. Current prices in the mid-to-high $40s are signaling a turn in the market. […]