Why do you think the American Empire is collapsing? I don't think internal strife is relevant for its international position. There were violent race riots at the height of its power. The Eastern Roman Empire lasted a thousand years after the fall of Rome while it was divided by power struggles and bitter conflicts about details of theology.

Now, the US is energy-independent, and has more population growth than Europe, Japan or China, while the dollar is strong compared to other fiat money, and the 'second army in the world' is being destroyed by not even the most powerful American weaponry.