The appointment of Mohammed bin Salman, son of the Saudi King Salman, as heir to the throne in June 2017 marked a watershed in Saudi and foreign and domestic politics, restoring Riyadh as a strategic U.S. ally in Middle Eastern politics and launching an unprecedented reform path in the Kingdom with the "Vision 2030" plan. The young prince’s rise to power coincided with the removal from the command centers of figures closer to the late King Abdullah and with an increasingly aggressive policy towards Iran, consolidated with the election of Donald Trump. The American leader chose Saudi Arabia as the inaugural stage of his first trip abroad in May 2017, ending the policy of openness towards Iran that had characterized the presidency of Barack Obama (2009-2017) that had led to the nuclear agreement being signed in July 2015, an agreement that was strongly criticized by Saudi Arabia and Israel. The relationship between the young crown prince, the president of the United States and the latter’s son-in-law, Jared Kushner, has also contributed to a gradual rapprochement between the Sunni Gulf monarchies and the State of Israel in opposition to Iran, and in favor of the re-imposition of sanctions against Tehran by Washington. Mohammed bin Salman’s rise to power coincided with a clear break with Qatar on June 5, 2017, which led to a redefinition of the Gulf Cooperation Council, led by Saudi Arabia and the United Arab Emirates, with implications for OPEC as well. Qatar’s decision, announced last December 3, to pull out of the Cartel in 2019, appears to be a direct consequence of that redefinition by Mohammed bin Salman. On the energy front, the politics of the young heir to the throne and his faithful entourage have been no less aggressive. The announcement in 2016 that the oil giant Aramco might be listed on a stock exchange, which has not yet happened, and a general review of the entire sector, has allowed Riyadh to establish relationships with foreign partners other than the United States, in particular China and Russia. The relationship with Moscow and personally with President Vladimir Putin, Iran’s main ally, was one of the most important moves by Mohammed bin Salman. The agreement signed at the end of 2016 to cut production between OPEC and the ten countries outside the Cartel led by Russia has resulted in an unprecedented level of cooperation between Riyadh and Moscow, cooperation based on a common interest in managing the price of crude oil.