Will China's warships trigger arms race with Japan?
After two months of Chinese incursions into Japanese-controlled waters in the East China Sea, President Hu Jintao has stated explicitly that China intends to become a maritime military power.
There is growing alarm in Japan, and growing support for right-wing politicians. Some of them are calling for a radical reassessment of relations with China - even for Japan to develop a nuclear deterrent.
Rupert Wingfield Hayes reports from Tokyo.