Why Taiwan is a major flashpoint between the U.S. and China

As President Trump takes part in a Beijing summit this week with Chinese President Xi Jinping, no issue will be more critical to Xi than Taiwan. Beijing has called Taiwan the core of China's core interests, with reunification, even by force, the center of Xi's agenda. In many ways, China and Taiwan are similar. They have a shared history, language and culture. But over the last nearly 80 years, Taiwan has become many things that China isn't. …