Mazu

According to the public notice issued by China, the sphere of the joint ground, sea and air exercise started from Nanri Island in the south and ended in the sea area opposite Jiangtian in the north, covering a sea area of approximately 6,000 square kilometres. It was only 30 kilometres away from the Taiwan-controlled Mazu Islands [Matsu].

The Nationalists used their control of offshore islands in a harassing blockade of China's central and southeast coasts. The Dachen Islands, two hundred miles south of Shanghai, interfered with trade to China's most important port. Mazu Island blocked the sea lanes to Fuzhou in Fujian Province, and Jinmen (Quemoy) blocked Fujian's second port of Xiamen.