Peng was still in command of China's armed forces when Mao ordered the shelling of Kinmen (Quemoy) and Matsu, islands off the coast of Fujian that were still held by the Kuomintang, in the late summer and autumn of 1958. Peng developed a strategy with his chief of staff, Su Yu, to bombard the islands so intensely that the morale of their defenders would collapse, which would eventually lead to the islands' surrender. Then, the PLA would then use the islands to launch attacks against Taiwan. The saturated shelling of the islands included over half the artillery in China and began on August 28. The attack included a co-ordinated effort to cut off the islands' air and sea supply lines.