From The International Herald Tribune:
China’s cancellation of a fence-mending visit by the Japanese foreign minister following Prime Minister Junichiro Koizumi’s visit to a shrine dedicated to Japan’s war dead highlights once again where the real threat to security in East Asia is emanating from.
The fact that Beijing called off Foreign Minister Nobutaka Machimura’s visit in the teeth of Defense Secretary Donald Rumsfeld’s arrival in Beijing further underlines the seriousness of the rift between China and Japan, and suggests that Washington should pay more attention to the problem, which threatens to spoil the inaugural East Asian Summit in December.
See also Sino-Japanese relationship on Wikipedia