The Chinese navy has announced that it will hold a major naval exercise off their coast in the Summer of 2004. Shortly after this news was released, the United States announced that two carrier battle groups would be sent to Japan during the Summer of 2004 to test the "surge" capability of battle groups that now stay home instead of taking regular six month cruises. There is also another carrier battle group that is normally stationed in Japan. At about the same time, a fourth carrier battle group will be passing by on its way home. It's rumored that the United States will be deploying a number of nuclear submarines, for training exercises,  to the western pacific at that time as well. Perhaps it not coincidental, but the Chinese navy won't be lonely while the practice. This sort of thing is common, as the best way to see how a potential enemy will fight (or try to fight) is to closely observe their large scale training exercises. Massing four American carrier battle groups in the same area also gives the Chinese a good idea of what they may be up against.