Not always. It could also be a form of patriotism, and to protect fair trade, so that healthy competition will be availible. The value of Yuan is set wrong, and the COMMUNIST China has not changed the value much despite warnings from US. We are facing an unhealthy and unfair trade, benifitting China that fills COMMUNIST China's pocket with money to have them build more advanced military equipments that could threat our country.
Not true, the Yuan was pegged to the American dollar but that ended quite some time ago. It is now based on a basket of currencies and is freely traded. the Yuan is now like the dollar, traders pay what they think is worth.