Saudi Arabia's elderly King Abdullah flies to the US today for checks for a back ailment, and Crown Prince Sultan is returning from holiday. Political stability in the monarchy is of global concern. The Gulf Arab state controls more than a fifth of the world's crude reserves, is a vital US ally in the region, a major holder of dollar assets and home to the biggest Arab bourse.http://www.independent.co.uk/news/world/middle-east/saudi-king-will-travel-to-us-for-treatment-2140325.html
Diplomats said the king's departure and the prince's sudden return indicate the kingdom, which has no elected parliament, is trying to prevent a power vacuum and reassure Washington and other allies.
King Abdullah is 86. His younger brother and heir, Prince Sultan, is 85.