That might seem logical, but downing a US spy plane over international waters was a pretty risky thing to do, and the military buildup near Taiwan seems counterproductive to a peace strategy, as does the North Korea standoff and the anti-Japan demonstrations. You'd think that if they were rational, they'd curb a lot of that stuff.
It's all perfectly rational. They are calibrating the limits and contours of our responses in various situations. We were not going to start an all out war over the spy plane. The military buildup with respect to Taiwan goes hand-in-hand with their overtures to the Nationalist party (carrot and stick). The North Korea situation is a classic proxy antagonist. They will keep the leash on their NK bulldog, but allow it to snarl away, keeping us off balance and distracted. The anti-Japanese demonstrations were completely effective in moving forward Chinese interests.