Abstract: The continuous actions by Chinese navy fleet across the international watercourses and straits of first island chain and the continuous military exercises of recapturing islands held by Japan and US, reflect the current situation of sea power game among China, Japan and US around the East China Sea and the control of the first island chain. This game is essentially a strategic competition around of the western Pacific military dominance among China, Japan and US. This article analyzes the specific manifestation of the game from the perspective of the Japanese isolated islands defense strategy, points out especially its strategic significance of blocking China. The defense strategy of isolated islands reflects not only the shift from the local defense to the isolated island defense, but also the strategic attempts of Japan's preventing China from rising up and breaking the first island chain by coordinating with US for AsiaPacific strategy, and Japan's focusing on the defense of military deployment of the Nansei islands. The essence of the defense strategy of isolated islands is a game of the western Pacific sea power among China, Japan and US.

Key words: defense strategy of isolated islands, recapture islands, Nansei islands, refuse to stop fighting