- 第一岛链 dìyīdǎoliàn First Island Chain(geopolitics) the first arc of islands off the East Asian continental mainland, including the Japanese archipelago, the Ryukyu Islands, Taiwan, and the northern Philippines
- 第二岛链 dì'èrdǎoliàn Second Island Chain(geopolitics) Second Island Chain, a strategic arc of islands stretching from Japan's Bonin Islands and the Mariana Islands to Guam and Papua New Guinea