Taiwan

Taiwan is a disputed territory between China and the island of Taiwan and it's people. The People's Republic of China claims this territory as theirs, as they won the civil war, and they did take the island of Taiwan. However, the people of Taiwan proclaim independence, as the government of Cheng Kai-Shek fled to Taiwan after losing the civil war and then established a temporary government on the island. The territory is essentially still Chinese, as it's position currently is a Autonomous Special Administrative region of China. The cause for independence is largely supported by the Western World, as the independence of Taiwan would humiliate the Chinese government and prove in incapability of China to extort the amount of control needed to subdue such rebellions. The independence of Taiwan would at the same time prompt multiple rebellions throughout Mainland China. This would dissolve China as a country, as all the Chinese provinces would proclaim independence.