Two nations, one strained history

There is disagreement and confusion about what Taiwan is, and even what it should be called.

Chiang Kai-shek's Republic of China (ROC) government, which fled the mainland to Taiwan in 1949, at first claimed to represent the whole of China, which it intended to re-occupy. It held China's seat on the United Nations Security Council and was recognised by many Western nations as the only Chinese government.

But in 1971, the UN switched diplomatic recognition to Beijing and the ROC government was forced out. Since then the number of countries that recognise the ROC government diplomatically has fallen to less than 30.

China itself regards Taiwan as a breakaway province which it has vowed to retake, by force if necessary. It says the ROC's lack of diplomatic recognition proves the world agrees there is only one China.

But Taiwan's leaders say it is clearly much more than a province, arguing it is a sovereign state with its own constitution, democratically-elected leaders and 400,000 troops.

After decades of hostile intentions and angry rhetoric, relations between China and Taiwan started improving in the 1980s. Taiwan relaxed rules on visits to and investment in China, and in 1991 proclaimed the war over. Although political progress since then has been slow, links between the two peoples and economies have grown sharply. Taiwanese companies have invested more than $50bn (£27bn) in China, and up to a million Taiwanese now live there, many running Taiwanese factories.

The United States is Taiwan's most important friend, and its only real ally. Their relationship was forged during the Second World War and the Cold War, and the US has promised to arm Taiwan and stressed that any attack by China would be of "grave concern" to the US.

US policy is now one of "strategic ambiguity", balancing China's emergence as a major power with historic US affection for Taiwan's success and democracy.

When in 1996 China tried to bully Taiwan with missile tests, President Bill Clinton ordered the biggest display of US military power in Asia since the Vietnam War, sending US Navy ships to the Taiwan Strait.