I am confused. What is the argument? Yes, for a long time the US was the only significant free market economy with a sufficient workforce and an ample supply of natural resources. The US workers' efficiency level has increased to the point that it is cheaper to have inefficient (and less expensive) labor produce goods for us. Other countries have lessened government control of markets and expanded the amount of available labor and resources worldwide. This is a good thing for everyone especially the US and is not a new idea:
Adam Smith
Some here have argued the zero sum game in economics (i.e. if one economy gains the other must, as a result, loose). In reality this is almost never the case:
zero-sum and
Pareto efficient
The only negative impact on the economy is Government regulation. All government regulations are taxes, not just monetary. An artificially imposed limit on supply (oil) is also a tax:
Economic taxes