Afghanistan: Appointment of deputy heir to throne stirs controversy in Saudi Arabia --- RIYADH, Saudi Arabia — When Saudi Arabia’s elderly king took the unusual step of naming a deputy heir, the move initially was welcomed as a sign of continuity in a country that soon will confront major questions over the future of its leadership. -- But in subsequent weeks, the announcement has stirred a rare outburst of dissent, revealing previously unacknowledged strains within the royal family and casting into doubt prospects for a smooth transition from King Abdullah’s rule. -- The king’s youngest brother, Muqrin, who was named deputy crown prince on the eve of President Obama’s visit in March, appears to be popular among ordinary people, who say he is not corrupt. He also is well-regarded by foreign diplomats, who describe him as likable and smart. -- But behind closed doors, royal tongues have been wagging about the manner in which Muqrin was chosen, the validity of his newly created title and his pedigree as the son of a Yemeni concubine who was never formally married to his father. -- “He is not a real prince; his mother was a slave and there are other brothers who are more competent,” said a former Saudi official who spoke on the condition of anonymity because criticizing the royal family is imprudent. “Nobody believes Muqrin can become king.” -- Some of the dismay has found a public airing on Twitter, which is better known in the Middle East for its role in fomenting social unrest but here also has found a niche as an outlet for disgruntled royals. -- “He was picked for this post because he is easily used,” tweeted an account known as @mutjahidd, which has 1.4 million followers and is thought to belong to a palace insider because its information often is accurate. -- The griping may merely reflect sour grapes among those left out in a looming transfer of power, or perhaps just the increased opportunities afforded by social media for tensions to come to light.