The political rationale is well known, so I'll add the economic one. The world economy has globalized around the principle of Comparative Advantage [1]. It mean

The political rationale is well known, so I'll add the economic one. The world economy has globalized around the principle of Comparative Advantage [1]. It means every country specializes on what it's relatively better at. It also means that your country can be in for a world of trouble if your comparative advantage changes. In turn, it means that a large adversary can attack you by turning the tables on your advantage. Automobiles are a large comparative advantage sector for the US, Germany and Japan. Displacing it - even if only by catching automakers on the wrong foot, as BYD and friends are trying to do - could result in a massive reorganization wave, coupled with recessions and political shocks. This is only possible because of China's size, of course. [1] https://en.wikipedia.org/wiki/Comparative_advantage https://en.wikipedia.org/wiki/Comparative_advantage