A good point, actually. However, at the risk of becoming slightly political, is it not the industry of the US that had made the country? Nike is a US company. Nike is the US.
Yes, but one must think more global... ie. Nike is a US company, who utilizes China's manufacturing base to produce the products while utilizing the USA's engineering and creative/design base to design the product, all the while utilizing resources extracted from all parts of the world (rubber from South America, oil from the middle east, etc...).
So while Nike is based in the USA, it is dependent on cooperation from all over the world, making it a global product. Also, realize that like many multi-national corporations, much of Nike's global earnings are not repatriated.