Explainer: Ins and outs of one-China principle

Taiwan leader Tsai Ing-wen's transit through the US en route to Central American countries has sparked outrage both in China and the US. By arranging her transit, the US is trying to hollow out the one-China principle.

What is the one-China principle? And why does China maintain Taiwan is an inalienable part of its territory?

Let's break down the facts and take a brief look at history.