Searching the far recesses of memory, you might recall a rather noisily introduced open ocean terror and WMD interdiction initiative, the Pounds per Square Inch (PSI).
Though one hears not nearly as much about the PSI now, it is still ongoing. Indeed, seven nations including Japan (and, encouragingly, the Pacific's least gung-ho power New Zealand) will be taking part in the PSI drill "Pacific Shield 07" on October 13-15 in the waters off Izu Oshima (a wonderful place for a three to five day vacation, by the way) and inside the harbors of Yokosuka and Yokohama.
This will be the second time Japan will host a training exercise for this multilateral security initiative--one that somehow does not violate Article 9 or require a policy statement from Ozawa Ichirō.
The Ministry of Foreign Affairs has its promotional material for the exercise. The still spanking new Ministry of Defense offers explanatory materials with a little more operational detail but without the historical background.
Later - I am being told that PSI does not stand for "pounds per square inch" but indeed stands for "Proliferation Security Initiative."