The difference is, of course, that the Gulf of Mexico is about as related to Mexico as New Mexico is to Mexico. That is to say, it's not theirs at all. Furtherm

The difference is, of course, that the Gulf of Mexico is about as related to Mexico as New Mexico is to Mexico. That is to say, it's not theirs at all. Furthermore, "America" is a general geographic region and not technically exclusive to the United States. We are both in North America.