DUBAI, United Arab Emirates (AP) — He is known as MBS and his rise through Saudi Arabia's corridors of power has been shockingly swift.

At age 31, Mohammed bin Salman already controlled the kingdom's defense policy and was overseeing a massive internal economic overhaul with the backing of his father, King Salman. His sudden appointment Wednesday to the position of crown prince places him as first in line to the throne, cementing his position as the driving force behind Saudi Arabia's major moves and seemingly charting Saudi policy for the coming decades. He is regarded as a bold and ambitious...