In discussing the perennial korea/japan issues, a commenter at the Marmot's Hole made a very interesting statement:
it is easier to understand korean way of thinking in the following manner. china, korea and japan are 3 brothers under confucian value. china, the oldest, korea, the 2nd and japan the 3rd. the older one should helps the younger, and be always respected, and be never disobeyed. so, even though china has had intervened politically over most of 5000years of korean history, koreans dont complain because it is the older brother. even no hard feeling about the fact china helped the north during the korean war. but japan, you know well what happend. furthermore sad and irritating thing is japan does not even think korea as the older brother and paid no respect.
While somewhat simplistic I think there is a considerable amount of truth to this. At least as to how the various parts see themselves in relation to each other. China certainly sees itself as the fount of all wisdom etc. just like an irritating older sibling. Japan is the pushy overachieving youngest always trying to get one up on its elders and Korea is the quiet one that doesn't say much but is prickly about perceived insults from its siblings. Of course a part of the problem is that Japan simply would not see itself as "younger" than Korea even though it is indeed so in most counts. For example there is considerable evidence that the Japanese Yamato kingdom - the real start of historical Japan - was partly or completely founded by refugees from the Paekche kingdom of Korea and Buddhism arrived in Korea some 300 years before it made its way to Japan, although contrariwise the Japanese Kana syllaberies were developed before Korea's Han'gul. However it is hard for anyone but the most ardent Koreaphile to deny that over the last century or so Japan has been the more dominant of the two - indeed it fought and won the Russo-Japanese war exactly 100 years ago primarily to confirm and extend its rule of Korea and Manchuria. In almost every respect Japan's short-lived overseas empire was a disaster for both Japan and the places it occupied and its legacy has helped poison national relations in the last 60 years.
In particular the "sibling rivalry" between Japan and Korea, which has manifested itself recently in all sorts of pouting about various insignificant specks of rock surrounded by fish-rich seas, has been a boon to China. As I noted in the Coprosperity Sphere post below, the Chinese should feel threatened by any alliance between the two "younger brothers" and other coastal nations. Indeed I sometimes wonder if the astoundingly tactless remarks made by both Koreans and Japanese are not in fact controlled by doble agents working for Beijing.
In a comment on the afore-mentioned post it was noted that the world could probably survive the economic collapse of China - nations such as India and Indonesia would undoubtledly be able to take up the slack - but I do not believe it would be in anyone's longer term interest for such a humbling to occur. The rulers of China have, with the partial excption of the communists, been remarkably inward looking throughout history. The lesson that should be learned from the various experiences of the three "siblings" during the 19th and 20th centuries is that in the long term ignoring the outside world is perilous but pushing to control it by force is no better. It is to be earnestly hoped that the rulers of the elder brother do not attempt to imitate their mongol and manchu forbears.