True, the DPJ, a would-be governmental party after the next election, opposes Japan’s current approach to the US-Japan alliance. Yet that doesn’t mean that the majority of the DPJ is against Japan’s contribution to international security like the Socialist Party was during the Cold War.
What DPJ leadership is saying is this: as long as international coalition efforts are based on UN Resolutions, Japan should dispatch the JSDF to them. Note that few years ago Ozawa surprised many people by publishing an article that suggested Japan’s participation in the ISAF in Afghanistan, a move even the LDP was reluctant to make.
It is also likely that the DPJ will change its security posture toward a more ‘realistic’ approach after coming into power, as the SPJ did in the mid 1990s. What the US should do is very clear – refrain from any unilateral military action and link its international security activities (for example, the war on terror) with other international security frameworks, especially with the UN, as much as they can. This seems more likely under Obama.
This makes it easier to engage US allies, including Japan, in these security activities. This is what Bush failed to do, and this is what Obama and Nye need to do, and probably will.
Tobias Harris’ post on the topic, a letter to Ambassador Nye, can be found here.