The global economy is an isolated system and is not in equilibrium: some countries have far lower quality of life (measured in household income per capita) than others. But the law dictates that this unevenness, like ALL unevenness, will quickly dissipate over time to a state that the system becomes completely even (disordered). No further exchange of energy or movement of particles could result in a more disordered (even) state.

In the global economy, this means all wealth generated from trade will go toward zero to a point that every country is equally rich with one another.

We are at a very uneven state (low entropy, high ordered), so America can profit from cheap labor of China while China moves up in its wealth.

As China moves up, the very source for its progress–its cheap labor–decreases. When China reaches the same level of wealth–when its labor is the same price as America–no further exploitation could take place. China and America then must exploit another country who is not at equilibrium, such a India. This process will continue until the world becomes even (most disordered).