There is no difference of opinion between the LDP and the DPJ over the basic legal prerequisites for Japanese involvement in military operations in and around Afghanistan. Both parties believe that such operations must be authorized by UNSG resolutions. However, the two parties differ when it comes to the specific application of this legal principle. The LDP is of the view that both a) the International Security Assistance Force (ISAF) and its activities and b) what the US named Operation Enduring Freedom (OEF; actually, OEF in Afghanistan in this post, as commonly accepted) and its participants have received such authorization, while the DPF asserts that only ISAF has done so. So, as far as the Constitution is concerned, the LDP position is that the Japanese Self-Defense Forces may engage in both activities, while the DPJ, with the victorious Ichiro Ozawa imposing his will on internal dissidents, allows to participation in ISAF only.
As a practical matter though, the LDP deems ISAF operations too dangerous and therefore has limited Japanese presence to OEF, where the JMSDF is undertaking the relatively safe, refueling operations on the open seas. On the other hand, the DPJ, prodded by Mr. Ozawa's openness to Japanese participation in ISAF - Mr. Ozawa has in the past shown a strong-pro US streak, and was the original proponent of "normal country" status for Japan, a concept that is more often associated with hawkish LDP politicians - is considering the matter, albeit with reluctance in many quarters. (Former party leader Seiji Maehara is one name that springs immediately to mind.) Thus, we have the intriguing situation where the LDP for practical reasons is limiting Japanese participation to modest proportions, while the DPJ is considering accepting the conclusions of its legal position (which has some force, if not quite a slam-dunk argument) and leapfrogging the LDP to the more dangerous phase of the operations against Al Qaeda and the Taliban. (There are reportedly DPJ voices calling for limiting participation to medical assistance and other civilian activities. It remains to be seen, though, if other nations with soldiers in Afghanistan will be willing, or even able, to baby-sit another gaggle of Japanese civilians and possibly lightly armed JSDF personnel.)
How will these legal and practical considerations play with the Japanese public?
OEF and the activities of ISAF in theory address different phases, or aspects of the war on terror; i.e. the former the continuing war against terror, and the latter the post-warfare stage "to assist the Afghan Interim Authority in the maintenance of security in Kabul and its surrounding areas, so that the Afghan Interim Authority as well as the personnel of the United Nations can operate in a secure environment" UNSC Res.1386 (2001). But both activities are directed against Al Qaeda and its protectors the Taliban (if at least in the case of ISAF by no means exclusively so). Thus, for all practical purposes, they end up serving the same objective. In fact, until the whole controversy blew up over the extension of the anti-terrorism act, I confess that I was not aware of this distinction, and I hazard to guess that the Japanese public in general did not know much better either.
Remember that a plurality of the Japanese public has been coming around to an admittedly underwhelming support for the continuation of refueling activities. And it's the same theater against the same opponents; one operation is safe, the other is hazardous (and, by itself, might not even be welcomed).
I think that the practical consideration will prevail with the safety-first Japanese public. Unless the 800,000 gallon controversy spills over into operations beyond USS Kitty Hawk, or even the initial stages of Operation Iraqi Freedom, I believe that the LDP position will prevail in the court of public opinion. A limited extension of two years for refueling operations only is definitely in the works, and, unless the potential budgetary repercussions of the ensuing delay of the next general Diet session become an overriding concern (I am now forced to add this caveat), will be passed within the year by a Lower House coalition supermajority revote. At least the Yomiuri editorial board seems to think so.
(Note) The Asahi editorial board is disappointed with Prime Minister Fukuda's answers in yesterday's Diet plenary, but officially remains agnostic. Mainichi is even more non-committal. The Sankei editorials no longer seem to be available after it replaced Mainichi as MSN's online news partner of choice. WTF?
Nikkei, Yomiuri and Asahi are collaborating on a joint website, joint distribution, and joint emergency production. Other newspapers are also welcome to join the party. At the same time, MSN has ditched Mainichi (or is it the other way around?) for Sankei. Whatever. Just give the world a deeper archive, so I won't have to keep copying the articles to my hard disk.