hahahah..! Great point!
It’s a combination of things:
1. Concern regarding the credibility of new US security guarantees
2. Traditional craziness of the stated policies of Hatoyama’s party
3. Growing ability of the PRC to shape the US’ future (debt)
4. Accommodation of some xenophobic forces inside Japan from both the left (all war is wrong) and right (non-Japanese soldiers should not be in Japan.
I think the biggest cause is #1, followed by #4 or perhaps #2.
You’re right —it’s nuts that with the Norks up there lighting stuff off that J could be even contemplating crazy stuff like this. But they are...just wow...
Maybe they will try to bring back the Greater East Asia Co-Prosperity Sphere. This time Japan will be the slave nation.