@Rochelle, Guyana could be sanctioned and Exxon continues and the money goes to escrow! It's offshore, Guyana has no means to inhibit Exxon's operations. Furthermore, the conflict will spread like wildfire and watch the international community.
The PNC are not the be all and end all to the rule of law. You don't just decide as you see fit and if you're hoping to blackmail the US via Exxon, I would be careful. The US has a "no holds bar" president!