If I get mugged in Paris and the French police fails to defend me, I can ask the US government to retaliate. The retaliation of the US government would be morally justified. It may or may not choose to retaliate based on the national interest.
Exxon's ownership of oil installations abroad is in the national interest.
Ridiculous. Commit an act of war in response to a mugging? Surely you cannot be serious.
I don't know why you pretend that this is libertarian. You can't even sue your own government for failing to protect you. Most certainly our government cannot initiate an act of aggression because some other government fails to protect you.
The government's job is not to protect you in such circumstances. You are responsible for your own personal defense and the government has ZERO responsibility to extend your personal protection zone across the sea into another country.
If this were true, then it would be far cheaper (and if your logic is correct this would be an acceptable and reasonable remedy) for our government to send armed military units to accompany you on your travels.
No, you're wrong. Exxon's troubles are Exxon's troubles. Not mine and most certainly not the U.S. government.