Saudi Arabia's king has appointed his son Mohammed bin Salman as crown prince -- replacing his nephew, Mohammed bin Nayef, as first in line to the throne. King Salman's decree also means Prince Mohammed bin Salman, 31, will become deputy prime minister while continuing as defence minister. Prince Mohammed bin Nayef, 57, has been removed from his role as head of domestic security, state media say. He has pledged allegiance to the new crown prince, his younger cousin. Prince Mohammed bin Salman could, potentially, lead Saudi Arabia for decades, heralding a long period of internal stability. However, the new crown prince is close to US President Donald Trump, and could ratchet up pressure against Iran -- which would raise tensions in the region.



