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.
After the "student revolution" in Iran, our embassy was taken hostage, and EDS (Ross Perots' company) employees were taken hostage. Our government responded by sending the helicopters on an ill-fated raid, and Perot responded by successfully freeing his men by force. When our medical students were endangered in Grenada subsequent to a coup there, Reagan sent in the marines to free them. All these were justified instances of application of force by our government to protect our citizens abroad. Or do you disagree?
According to libertarianism the government has no other role but to protect its citizens, everywhere. In the civilized world, our government can delegate that job to other national governments. If a national government fails to protect our citizens, our government is justified in responding; the only remaining question is the degree and manner of response.