- 第一岛链 Dìyī Dǎoliàn First Island Chain(geopolitics) First Island Chain, a strategic arc of islands including Japan, Taiwan and the Philippines
- 第二岛链 Dì'èr Dǎoliàn Second Island Chain(geopolitics) Second Island Chain, strategic arc of islands stretching from Japan's Bonin Islands to Guam and Papua New Guinea