The Bamboo Curtain was the east Asian version of the Iron Curtain. It marked the border around the communist states of East Asia, especially the People's Republic of China during the Cold War, but excluding the eastern Soviet Union. The term was less often applied to the border between North and South Korea or the flexible border between Communism and the west in Southeast Asia.
During the Communist Cultural Revolution in China, the Curtain served as a lock-down of sorts, forbidding entry into or passage out of the country without explicit permission. Many would be capitalist refugees were blocked from escape in this manner.
The term "Bamboo Curtain" was used less often than the term "Iron Curtain" in part because while the latter remained relatively static for over 40 years, the former shifted constantly. It was also a less accurate description of the political situation in Asia because of the lack of cohesion within the East Asian Communist Bloc which ultimately resulting in the Sino-Soviet split; The Communist governments of Mongolia, Vietnam and later Laos were allies of the Soviet Union, while Cambodia's regime of Pol Pot was loyal to China. Shortly after the Korean War, North Korea swore allegiance to neither the USSR or China.
Improved relations between China and the United States during the later years of the Cold War rendered the term more or less obsolete, except with reference to the Korean Peninsula and the divide between Allies of the US and the USSR in Southeast Asia.