You might want to add Brenton Woods Agreement and later the petro-dollar. The monopoly of the world reserve currency.

In short US economical imperialism of the global economy allows the US to run a huge trade deficit and print as much money as they want. The strong dollar also means they can buy cheap. An asymmetry that has little to do with their productivity (unlike in the case of Germany).

But that is now slowly but surely coming to an end as we are entering a multi-polar world.

The US is richer, now, yes certainly, but ask yourself on what fundamentals those riches are based upon. And what happens to the US economy once that hegemony is lost....Then re-ask yourself the above question:)