Long-stewing problems in one region don’t go away just because another region is at center stage. While Brexithas raged, 3,000 miles away in Riyadh the Saudi royal family, beset by the long-term plunge in petroleum prices, is racing to transform the kingdom’s oil-centered economy. If it ultimately fails to realize its grand plan in an already convulsive Middle East, the impact would be incalculable.

QUICKTAKESaudi Arabia’s Strains

Saudi Arabia, the largest economy in the region and an important strategic ally of the U.S., can’t subsist on oil money indefinitely. Its plan includes a landmark sale of up to 5 percent of the national oil company, possibly the world's biggest IPO, to help build a sovereign wealth fund that could top $2 trillion.