China defeated Vietnam in a naval altercation while attempting to establish oceanographic observation posts on the Spratly Islands.

The Johnson South Reef skirmish took place on 14 March 1988 between military forces of the People's Republic of China and Vietnam, on the Johnson South Reef in the Union Banks region of the Spratly Islands, in the South China Sea.

The Spratly Islands are a disputed archipelago in the South China Sea. Composed of islands, islets, cays, and more than 100 reefs, sometimes grouped in submerged old atolls, the archipelago lies off the coasts of the Philippines, Malaysia, and southern Vietnam. Named after the 19th-century British whaling captain Richard Spratly who sighted Spratly Island in 1843, the islands contain less than 200 ha of naturally occurring land area that is spread over hundreds of square km of the South China Sea.