Ezra Vogel, Harvard professor emeritus and longtime Asia hand, said in an interview that, with the incoming Obama administration, the U.S. will opt for increased cooperation with China over a gamut of international issues, displacing a portion of such efforts with Japan. From The Japan Times:
“It’ll be easier to get the Chinese government to make an agreement, because when they make it, they can enforce it much more quickly,” said Ezra Vogel[…]
“So on international issues, even though Japan is our ally and our friend, for a lot of problems we’ll be talking more to China because they can solve issues more and they are now beginning to play a big role,” Vogel said[…]
Vogel commented on the expectation of reciprocal cooperation from other countries, as well. Along such lines, Vogel noted Japan’s increasingly poor track record:
[…]more than 10 years have passed since an agreement to relocate the U.S. Marine Corps Air Station Futenma in Okinawa was reached, but the move is nowhere near happening. On North Korea, Japan’s tough stance and strict focus on the abductee problem is a stark difference with the other nations in the six-party denuclearization talks.
“If Japan only stresses the abductee issue and does not show signs publicly of cooperating, then there will be increasing frustration,” Vogel said.
For an official statement of Obama’s stance on China, see this CDT post.