More on the above...

http://in.reuters.com/article/2012/0...8KB3S620120911

Japan brushed off stern warnings by China and bought a group of islands on Tuesday that both claim, in a growing dispute that threatens to deepen strains between Asia's two biggest economies.

Chinese official media said Beijing had sent two patrol ships to waters surrounding the islands to reassert its claim and accused Japan of "playing with fire" over the long-simmering row. The army warned that further, unspecified steps could follow.
I would not expect the Japanese to back down, or to be intimidated.