Foreign corporations operating in China have never enjoyed a simple or easy life. But things have suddenly become much harder for South Korean companies trading in the Middle Kingdom: they appear to have been set the task of changing their own government’s security policies as a condition of doing business.

That is the impression given by Chen Hai, a Chinese foreign ministry official who visited Korean companies last week. As reported in the Financial Times, Mr Chen warned them that their business in China would suffer if the South Korean government deployed a US ballistic missile shield designed to protect against North Korean aggression.

Even if these threats prove effective, Beijing will damage its own economy and regional stability if it takes this route. With Donald Trump soon to enter the Oval Office, the last thing the world needs is the further politicisation of international commerce.