China's military will be misbehaving in the next few months. The 2001 Hainan Island incident that everyone has forgotten about will set the tone for the early encounters - unless we re-set it now.
Besides the obvious testing of Obama, they also have an export-based economy in the process of crashing and burning. If they're going to keep up the rabid nationalism they've been feeding for the past couple years, they have to give people something to cheer about while the factories in Shenzhen are going dark. And that would be military posturing with the U.S. with its growing Navy (and its military space force - yes, really).
The next few months are crucial. By standing firm now - over Tibet, North Korea, and Myanmar, and keeping our alliances with Japan and India strong - we can assure a positive, open future for both the U.S. and a freer China. There aren't many things more important in the twenty-first century than that.