Guanbi policy
The guanbi policy or closed port policy was a military blockade policy of the government of the Republic of China against the Communist party of China since June 1949. It was carried out by the ROC navy from the Bohai to the South China sea.
In 1950, it was expanded to blockade the entire mainland's shoreline, with the intent of crippling the CPC controlled mainland's economy. After 1950, it gradually evolved into a military blockade across the Taiwan Strait with the ROC targeting the PRC and hijacking civilian ships.