Our political system has never been, and was not designed to be, harmonious and without rancor. Quite the opposite. And in every generation there have been ignorant hysterics screeching, "Oh my gosh! It's never been this bad!"
Our military is unmatched.
Our economy is still the largest and most important in the world. We innovate, we produce, we export, we import, we educate, and we influence the rest of the world.
Private, competitively-based education in the US is the best in the world.
You are right about the US military. But as for the rest ....
I suggest that the Chinese economy is the more important. The US only survives because of loans from China; if they stop lending you are in big trouble. Lots of countries innovate as much as the US. You produce less and less. You export a bit and import stupendous amount. At the top - MIT say - US education is the best, as you say. But lower down the scale it is poor. International tables of children's attainments indicate that your pupils perform badly.
And there is something wrong when you spend more on healthcare than any other developed country and have about the worst outcomes on almost every measure.
The Chinese are not more important. They are still a third world shithole, full of slaves that work for a communist government. They depend a lot more on the US than the US does on China. If we stopped using them as slave labor and had our shit manufactured anywhere else, they would be in a world of hurt.