How did China’s 11-dash line become the 9-dash line?

The 11-dash line was originally introduced in 1947 by the Nationalist government of the Republic of China under Chiang Kai-shek to assert sovereignty over the South China Sea.1

Following the Chinese Civil War, the Chinese Communist Party under Mao Zedong established the People’s Republic of China and claimed successor status to the previous government's territorial assertions. In doing so, the new government in Beijing modified the original 1947 map by removing two dashes, effectively changing the 11-dash line to the 9-dash line.1

While the line is commonly referred to as the 9-dash line, it remains a source of significant international tension, as its vague legal basis and geographic coordinates conflict with the United Nations Convention on the Law of the Sea.2