As Japan's Self-Defense Forces prepare to respond to the challenges of operating in a combined way with U.S. forces, the question of whether Japan's own military services can operate in a joint way might seem to come first. I've had a lot of experience in this realm: I was with the Joint Staff Committee in 1997; I was the Joint Staff Committee's "Fifth Joint Staff Room Head," the so-called J5, for a year; and at that time, I was involved in the revision of the Japan-U.S. Defense Guidelines.

http://www.armedforcesjournal.com/2005/12/1232362