The shakeup in Saudi politics is complete

The big news in the Arab world today is the ascension of Mohammed bin Salman. He's now the heir to the throne of his 81-year-old father. At just 31-years-old himself it puts him in-line to rule the kingdom for many decades.

Bin Salman stormed onto the scene two years ago when he came to lead energy and defense policy. Last year he led a plan to lead Saudi Arabia away from oil dependency. Today his father undid his late brother's decree that had put Muhammad bin Nayef as the incoming leader. The 57-year-old bin Nayef was relieved of all his roles.

He himself came to be the leader-in-waiting in 2015 after Muqrin bin Abdulaziz was relieved despite a decree from for King Abdullah saying he "may not be modified or changed in any way or form by any person whoever it may be."

But it's Bin Salman in charge now and his reign will have massive implications for the Middle East and the world. With his proxy wars in Yemen, Syria and now Qatar, he's chosen to be assertive and he also appears to have won over US President Trump.

Certainly some of Saudi Arabia's enemies would like to use the transition to sew instability. What comes next will be intriguing.