I think the distinctive feature about Japan and the US is that both governments are (through very different mechanisms) under the sway of their own internal pre

I think the distinctive feature about Japan and the US is that both governments are (through very different mechanisms) under the sway of their own internal pressure groups. This makes them unable to take a reasonable bargaining stance. Perhaps this is a symptom of Japan's and America's waning power? In the past, they could afford to take less reasonable stances because they were dominant in their respective spheres, so their political classes had no incentive to clean things up.