Following the signing of the nuclear deal between the P5+1 and Iran in late 2015, relations between Saudi Arabia and the United States have become increasingly fractious. Since then, with questions about the release of a number of classified pages of the 9/11 commission report, along with increasing concerns at the kingdom’s human rights record, the relationship between Riyadh and Washington is at the lowest point in decades. This briefing by Dr Simon Mabon offers an explanation for the deterioration of the relationship between the two.