Introduction
Taiwan has one of Asia's few functioning democracies and one of its strongest economies. But for the island's 23 million people, the future is overshadowed by an unresolved dispute with China.
China sees the island as a breakaway province which should be reunified, by force if necessary. Hundreds of Chinese missiles now aim across the Taiwan Strait to bring home the point.
Both sides are used to dealing with this fraught relationship, and closer economic ties may eventually make conflict less likely. But until that happens, any flare-up over Taiwan would have much wider implications. Most importantly, it could quickly suck the US into conflict with China, because of US security assurances to Taiwan.
BBC News Online looks at the issues behind what some analysts see as one of the world's most dangerous flashpoints. Click on the links above to find out more.
China has stated that they will cease all military exchanges with the United States in response to a  weapons deal with Taiwan going ahead. He Yafei, Chinese Vice-Foreign Minister, said that there would be a "serious negative impact" with regards to the relationship between the US and China.

Taiwan and mainland China have been ruled by separate governments since 1949, and neither recognize each other's independence. In an effort to regain control of Taiwan, the government in Beijing has been open to running the island like Hong Kong, in a "one country, two systems" manner, but people in Taiwan support the status quo. The Chinese defense ministry said that they had "decided to suspend planned mutual military visits". They "strongly demand" that the United States "respect the Chinese side's interests," calling for the proposal to be rejected.

China summoned the US Ambassador to China, Jon Huntsman, to warn the US Government about the consequences, and to urge for cancellation of the deal. The Pentagon proposed the deal, that was first promised during the later days of the Bush administration, to Congress earlier.

Yafei issued a statement on the Foreign Ministry website stating that "the United States' announcement of the planned weapons sales to Taiwan will have a seriously negative impact on many important areas of exchanges and co-operation between the two countries."

However, the US is defending itself. "Such sales contribute to maintaining security and stability across the Taiwan Strait", Laura Tischler, spokeswoman for the US State Department, said.

Beijing is threatening to review co-operation on major issues and impose sanctions on companies selling arms, even though US companies are banned from selling arms to China as a result of the Tiananmen Square massacre in 1989, so it is not clear what the effect will be. A Chinese defence ministry spokesman said that the sanctions reflected the "severe harm" the deal would have. A foreign ministry spokesman stated that there would be "repercussions that neither side wishes to see" if the deal went ahead.

Taiwan, one of Asia's few functioning democracies, welcomed the proposal, with Taiwanese president Ma Ying-jeou being quoted as saying "It will let Taiwan feel more confident and secure so we can have more interactions with China."

The arms deal includes UH-60 Black Hawk helicopters, communications equipment and MIM-104 Patriot missiles, but does not include the F-16 fighter jets that Taiwan's military were looking for. The US is legally obliged to supply Taiwan with defensive weapons under the Taiwan Relations Act 1979.

In 2003, an unnamed US briefing stated that "the US would have to get involved if China tried to use coercion or force to unilaterally change the status of Taiwan".