I doubt that "eternal and unchanging interests" applies, since technology aqnd political changes in other countries could easily change some of our interests. For example, if we replaced most of our use of imported oil with another energy source then we would be much less interested in spending billions of dollars protecting our access to middle-eastern oil.

Or say our demographic makeup shifted enough to make us more than 50% Catholic and Spanish-speaking. That would certainly change some of our interests as a nation!