This new oil price drop simply is crushing producers' currencies in foreign exchange markets. The combination of the petrodollar losing its ability to act as a store of value, combined now with exchange rate blues, may be the straw that breaks the producer "camel's back" in respect to OPEC and dollar denomination. Such a moment would seem ripe for Russia and Iran to begin a gradual challenge to Saudi's leadership of the OPEC cartel and to the dollar-denominated energy system, if enough OPEC members and other producers are prepared to rebel. Iran has been lobbying hard in this direction.
The final nail in Prince Bandar bin Sultan's coffin did not come when the former Saudi intelligence chief lost control of the Syria file to his political rival the interior minister Prince Mohammed bin Nayef. It was when Bin Nayef went to King Abdullah and obtained from him a written mandate to keep the file.