Tokyo is monitoring China's rapid military buildup and remains on alert in the wake of recent incidents, including the intrusion of a submarine into Japanese territorial waters and frequent operations by its marine research vessels nearby, according to an annual report on defense released Tuesday.
The defense white paper, endorsed by the Cabinet, notes that China's defense budget increased by more than 10 percentage points over the past 17 years.
"It is necessary to keep paying attention to these modernization trends and to carefully evaluate whether the modernization of China's military forces exceeds the level necessary for its national defense," the paper says.