Reports in the Sydney Morning Herald indicate that during three way talks, both the UK and Australia have informed Japan that they are giving strong consideration of pulling out of Iraq by mid 2006.
This has upset Japan for a couple of reasons.
Japan was planning of announcing an extension of their commitment in Iraq, and Australian forces the troops defending the non-combat troops from Japan. At this point Japan must have the UK and Australian forces in place, or it is doubtful they can continue their mission.
It was very proper for this heads up to be given, but the timing has to be hard on Japan's planning. You also have to expect that the US has been given the same notice, and is working hard to keep the UK and Australia in line.
Of course, in light of todays suicide bombings and attacks, and the further decline of stability in the once quite south, keeping them in place will not be an easy argument for the US to win.