Mad Minerva notes this list of ten myths about China that we should all keep in mind. I heartily endorse these corrections of myths. With one partial exception:
7) China's decline will make our lives easier. China's decline may make the challenge for the United States more difficult for at least a generation. It could play out for a long time even as China grows more aggressive with more lethal weaponry (e.g., what to do with surplus males?). Arguably both Germany and Imperial Japan declined beginning after World War I and continuing through the disaster of World War II. Russia is in decline by all useful metrics. Even so, it invaded a neighbor not too long ago. A declining, nuclear-armed nation with a powerful military can be more problematic than a rising, confident nation.
I agree that a power that becomes frustrated may become a military threat that a confident and growing power might not become since it thinks the world will fall into their orbit without effort, in the long run. But a rising China could still pose that military threat. It isn't a cut and dried choice of war or no war. A China that rises only so far and then loses ground, on the other hand, has tighter limits on the damage they can do if they go to war. And while I would be happy to have a prosperous China join the international system as a defender of the system (does Britain get upset that America surpassed them to do the job they once did?), we did do just fine without China as a major economic player and still do fine without China as a major player defending the international system.
China is a challenge. One we can welcome as a friend, lose to, or defeat. The path is up to China. We spend too much time worrying about the effects of our decisions as if China is sitting there watching and waiting to react to America alone rather than reacting to internal and multiple external factors that our role is only one part of.