The Johnson South Reef Skirmish was an altercation that took place on 14 March 1988 between Chinese and Vietnamese forces over who would control the Johnson South Reef in the Union Banks region of the Spratly Islands in the South China Sea.
Background
The 14th UNESCO Intergovernmental Oceanographic Commission (IOC) agreed that China would establish five observation posts for worldwide ocean survey, including one in the Spratly Islands, and they commissioned China to build an observation post there in March 1987. The Delegate of the People's Republic of China (PRC) spoke highly of GLOSS (Global Sea Level Observing System) during the meeting of the UNESCO IOC in Paris, but he noted what the PRC considered to be a few mistakes in the text of Document IOC/INF-663; for example, "Taiwan" is listed as a "country" in relevant tables contained in the document. The scientists from the GLOSS did not know that the PRC claims that Taiwan is not a separate country; nor did they know about the territorial disputes in the South China Sea. They agreed that China would install tide gauges on its coasts in the East China Sea, and on what the PRC calls its Nansha Islands in the South China Sea. The scientists did not know that Taiwan occupied one of the Spratly Islands, but (despite its territorial claims), at that time China occupied none. After numerous surveys and patrols, in April 1987 China chose Fiery Cross Reef as the ideal (from their point of view) location for the observation post, because the unoccupied reef was remote from other settlements, and it was large enough for the observation post. On the other hand, Johnson South Reef in the Union Banks sunken atoll, (150 km east of Fiery Cross Reef), is close to the Vietnamese inhabited Sin Cowe Island (also in the Union Banks), and it is also within the 200-nautical-mile Economic Exclusion Zone of the Philippines; in other words, Johnson South Reef is in a high profile and highly disputed area. In January and February 1988, Vietnamese forces began establishing a presence at surrounding reefs, including Collins Reef and Lansdowne Reef in the Union Banks, in order to monitor Chinese activity. This led to a series of confrontations.
Course
China's account
On 13 March, the frigate Nanchong detected People's Army of Vietnam (PAVN) armed naval transport HQ-604 heading toward Johnson South Reef, transport HQ-605 heading toward Lansdowne Reef, and landing craft HQ-505 heading toward Collins Reef in a simultaneous three-pronged intrusion upon the disputed reefs.
At approximately 07:30 on Johnson South Reef, Vietnamese troops attempted to erect the Vietnamese flag on the reef. It was reported that PAVN Corporal Nguyen Van Lanh and PAVN Sub Lieutenant Tran Van Phuong argued over the flag raising with People's Liberation Army Navy (PLAN) sailor Du Xianghou, which led to a pitched battle between the opposing forces on the reef. In response, Vietnamese forces, with naval transport HQ-604 in support, opened fire. PLAN forces and the frigate Nanchong counter-attacked at 08:47 hours. Transport HQ-604 was set ablaze and sunk.
At 09:15 hours, the frigate Xiangtan arrived at Lansdowne Reef and found that nine Vietnamese marines from transport HQ-605 had already landed. The frigate Xiangtan immediately hailed the Vietnamese and demanded they withdraw from the reef. Instead, the Vietnamese opened fire. HQ-605 was damaged heavily and finally sunk by the Chinese.
Vietnam's account
In January 1988, China sent a group of ships from Hainan to the southern part of the South China Sea. This included four ships, including three frigates, dispatched to the north-west of the Spratly Islands. The four ships then began provoking and harassing the Vietnamese ships around Tizard Bank and the London Reefs. Vietnam believed this battle group intended to create a reason to "occupy the Spratly Islands in a preventive counterstrike".