Of course, the US government has a role in the other attractive attributes the US has, but I personally think that role is exaggerated. I think the US would still be an economically dominant world power if it had the government of, say, Germany.
You are very first-world centric, then. While I am no interventionist, you are discounting the role the US Military has worldwide on trade, peacekeeping, and other vital roles it actually does a good job at when it's not fucking things up (which is often).
>> I think the US would still be an economically dominant world power if it had the government of, say, Germany.
Including the racial makeup of Germany and the immigration policies?
Germany has a population 25% as large as America, and a GDP 18% of America's. So maybe if you ignored history, geography, a potential nonlinear relationship between population and economic domination¹ you could claim this discrepancy is solely due to racial differences between the populations of America and Germany. But I'm pretty damn skeptical of that.
1: for instance https://en.wikipedia.org/wiki/Winner-take-all_market