I think this idea of "worth fighting for" needs some unpacking, though. If by that, we mean contributing to the good of the nation with all of our talents, intelligence, and so on, then great! By that metric, most countries would be worth fighting for, in the sense of contributing to their good and the welfare of their citizens.
But if, by "worth fighting for" we mean American exceptionalism justifies warfare beyond your borders, profiting from the sale of weapons (whose use results in death, destruction and misery for thousands, if not millions), and so on, then I think that claim needs much more scrutiny.
Why? In what way does it offer something different or more for human flourishing than other first-world countries?
Land of immigrants (not just lately, not just moderately, but for centuries), where ethnicities mix together in great numbers. (Not just for recent times, but many generations) The nation where we continue to learn whether or not people of different ways, backgrounds, culture, origins can truly live together, longer term...without a falling apart, disintegrating.
Sometimes it looks shaky, like it might be going down.
But, so far still treading water, well over 2 centuries....
The project still is alive. The experiment.
But its not yet a sure thing, even though we've made it 230 years.
It could still collapse into chaos and bloodshed, and the "center not hold".
Man's hope for peace in this world.
Still could fail, and if that happened, that would suggest the project cannot succeed: brotherhood of man can't last, until Christ returns.
See, it's the "last best hope" Lincoln said. That's a viewpoint.
In the end, if racial harmony fails here, it probably could not succeed anywhere in only human ways,
long term.
But we that believe in Christ have a
better hope. We have the only ultimate and best hope.