The speed and scale of China’s island-building spree have alarmed other countries with interests in the region. China announced in June that the creation of islands — moving sediment from the seafloor to a reef — would soon be completed. Since then, China has focused its efforts on construction. So far the country has built port facilities, military buildings and an airstrip on the islands, and recent imagery shows evidence of two more airstrips under construction. The installations bolster China’s foothold in the Spratly Islands, a disputed scattering of reefs and islands in the South China Sea more than 500...
