Diseases don't respect borders. You know, just at the edge of the American border, that isn't the edge of diseases. We need to be sure that we're looking worldwide. And it is in our security interest, as well as our moral interest, to pay attention to the rest of the world.
A definition is nothing else but an explication of the meaning of a word, by words whose meaning is already known. Hence it is evident that every word cannot be defined; for the definition must consist of words; and there could be no definition, if there were not words previously understood without definition.