At a time of shifting power dynamics in Asia, Japan faces pressing security challenges. Of the 400 remote islands that serve as markers for determining Japan's territorial waters, only about 50 are inhabited. But no group of islands poses a bigger challenge for its security than the Senkakus, a clutch of five uninhabited islets and three rocks.
This challenge is compounded by demographic and military trends. Japan has barely one-tenth the population of China's. Moreover, its population is not just aging but also shrinking significantly; it declined by nearly a million just between 2010 and 2015.
About a decade ago, Japan's defense budget was larger than China's. But now China's military spending surpasses the combined defense budgets of Japan, Britain and France.