Well, so I got that timeline wrong. The Sino-Soviet split was in the '60's, Nixon's diplomacy in the '70's. He he, nobody look at me. :-|

However, restricting this argument to Japan, rather than all of Asia, there is still one more data point which I haven't mentioned (and I double checked the timeline on this.) Their 'lost decade' - not just a decade, but heralding a long-term decline in their power - was preceded by an international currency intervention, the Plaza accord. While this wasn't necessarily against Japan's will, it was led by the US, and thus still follows this theme of foreign events dictating Japan's internal political situation.

So, in short, Japanese colonial ambitions can be traced back to the unequal "Treaty of Amity and Commerce" from 1858, which was an American attempt at colonialism (even if feeble by European standards.) After their defeat in WWII, Japan put their economy into overdrive - at the bequest of the US. Finally, when outside economies (led by the US) expressed discomfort at how hot Japan's economy was, Japan figured they had done all they needed to in terms of war reparations, and they've kind of let things drift since then.

So this explains Japan; however without China this theory isn't be consistent enough to generalize to North Korea. Assuming Japan is unique as an Asian country can at least help explain why Japanese re-armament is such a potent issue in the region though. We can threaten to encourage them to rearm in order to keep other countries in the region in line (particularly China, to use against North Korea, because North Korea themselves won't respond rationally.) Sort of like our relations with Israel, our relations with Japan can set the tone for our dealings with everyone else in the (respective) regions. In fact, in my view, it's possible to draw some strong parallels between these two parts of the world: Japan is equivalent to Israel; North Korea is equivalent to al-Qaeda, and the rest of East Asia is equivalent to moderate Islam. The connection between these two parts of the world, as I see it, is the US, which sees both Japan and Israel as its post-WWII responsibilities.

Having made this connection that US policy in the Middle East and East Asia is colonialism, some interesting ideas present themselves. These regions are too divided to mount an effective resistance a la India to Britain, so there is no vulnerability there. So we could keep the status quo; on the other hand we could also make this argument in order to withdraw from the Middle East process. (This perceived responsibility could potentially be a vulnerability, because there will never be a settlement which will satisfy the Palestinian side, and being in charge of the process simply moves the bulls-eye from Israel to us.) If China can manage the North Korean situation responsibly, then the US can be proactive about Japan not re-arming; and by the same token if the parties in the Middle East expect the US to find a solution, they will never learn to solve problems on their own. The term 'colonialism' is enough of an anathema to everyone that its use will stir immediate opposition, if a coherent argument can be made for its use. Solutions for the Middle East conflict and the problems on the Korean peninsula don't necessarily have to be made piecemeal. With some creative historical reinterpretations, it's possible not only to kill two birds with one stone, but make each individual solution stronger as well. Getting both of these international sub-systems to govern themselves without American help would allow us more flexibility to prepare for new kinds of threats; and also reduce the chances of us screwing things up and being held politically viable.

Really I'm just throwing some thoughts around - I don't know if this is any more viable than any of the other ideas I've had. If this methodology can produce ten bad ideas and one good one, it's still a useful exercise.