China doesn't get along with friends, neighbors, or enemies:
China has a growing list of problems with its neighbors, both the ones who are allies (North Korea, Burma, Pakistan) and those who are not (all the rest.) The "allies" are a sorry lot; all of them failed states with troubled economies and inept governments. The other neighbors are increasingly hostile because of the nationalistic polices of China, which have led to bullying and threats. China has become more vocal about claims on the territory of its neighbors. This has caused the neighbors, despite many differences they have with each other, for form a growing anti-China coalition.
China is big. But they aren't big enough to beat everyone--especially if we weigh in the balance.
UPDATE: The boat is getting bigger, but it might be taking on water.
I've never been in the camp that sees China as on a continuous uphill slope on the way to replacing us as the global power. But I've never believed China needs to get that strong to be a threat to us or the world we've built and defended.