They’ve been dubbed the two princes, the rising powers behind the thrones in the budding strategic alliance between the House of Saud and the House of Trump. Jared Kushner married into Donald Trump’s family and now serves as the president’s senior advisor. His portfolio of domestic and foreign responsibilities seems to grow heavier by the day. Deputy Crown Prince Mohammed bin Salman is the Saudi defense minister and head of the state oil monopoly. More importantly, he has emerged from a crowded field of royalty to be second in line to King Salman, his 81-year-old father, who inherited the crown...