I am a big fan of Zakaria's, as I think he has some keen insights into how the world functions economically socially and in terms of international relations. Unlike Thomas Friedman, he's not just an economist, he takes many facets of the situation into account. This is also true of The Post-American World.
In this work, he suggests that America's competitiveness has not decreased, as many people believe. He says that, instead, other economies around the world have become more competitive in the world market, especially with globalization. He means countries like China, Brazil, India and even Russia.
America, according to Zakaria, has contributed to the rise of the rest with its insatiable demands for energy, manufactured goods, and profits. As the US represents 25% of the world's economic activity, we have been the engine of the increasing competitiveness of other nations.