Political status of Taiwan

The political status of Taiwan is a difficult situation that many people disagree about. There are two countries in the world that call themselves China. The People's Republic of China (PRC) is the country most people think of when they hear the name China. The Republic of China (ROC) also calls itself China. It is better known in most of the world as Taiwan.
Taiwan was a part of China for thousands of years. After the First Sino-Japanese War, Taiwan and Penghu was illegally taken by Japan. After World War II, the Japanese gave up any claim to Taiwan, but did not say who they were giving control to. At the time, the Republic of China governed all of China, and represented China in the United Nations. After losing a civil war in 1949, the ROC government fled to the island of Taiwan, leaving the PRC to control mainland China. The PRC says it owns the island of Taiwan (which is also known as Taiwan province) and the other islands. The ROC says that it was--and is--the rightful government of China, including mainland China, Taiwan, and Mongolia. In 1971, the ROC lost its United Nations seat as China. The seat was given to the PRC instead. This made the PRC the recognized government of China internationally. The major problems are about whether Taiwan is a part of the PRC or should be an independent country.
Current status
Today, the ROC (Taiwan) is a fully democratic society, with its own economy, currency, military, and elected officials. The Chinese mainland is ruled by the communist PRC government. Most countries have accepted the PRC as the leaders of China. Several countries, including the United States, have been careful to not say officially which parts of the original China are part of the PRC. 14 countries have official diplomatic relations with Taiwan. Those who don't usually have un-official de facto embassies and do business with Taiwan mostly as normal, aside from recognizing it as a country.
The current state of Taiwan and China is called the "status quo", which means neither side is trying to change the way things are. However, the PRC often threatens to use military force to change the situation and bring Taiwan under PRC control. Some people in Taiwan want Taiwan to formally become the Republic of Taiwan, an independent country. This would change the status quo also, and many Taiwanese prefer not to do this, in order to maintain peace. In opinion polls, only a very small percentage of Taiwanese people want to rejoin with the mainland.
Views by other countries
Today, most countries of the world see the PRC as China. Most countries however still have a very close economic and cultural relationship with Taiwan, even if they have major tensions with the PRC.
Problems
The relations between the PRC and Taiwan are tense. The PRC believes that Taiwan is a part of the PRC. The government of the PRC has said that if the people of Taiwan vote to become the Republic of Taiwan, that they will invade Taiwan and stop this from happening. In March 2004, they passed a law that will allow China to invade Taiwan if Taiwan tries to leave the PRC and become an independent country. This law has caused problems with the people in Taiwan. It has caused even more people in Taiwan not to want to be a part of PRC China.
Another issue is how a war for Taiwan would grow to include the United States, who has said it would help defend Taiwan, and Australia and Japan, who also hint at helping Taiwan in case of war.