Since 2018, the United States has been tightening its laws to prevent its rivals from buying into its sensitive sectors – blocking investments in everything from semiconductors to telecommunications.
But the rules weren't always so strict.
In 2016, Jeff Stein, a veteran journalist covering the US intelligence community, got a tip-off: a small insurance company that specialised in selling liability insurance to FBI and CIA agents had been sold to a Chinese entity.
"Someone with direct knowledge called me up and said, 'Do you know that the insurance company that insures intelligence personnel is owned by the Chinese?'" he remembers. "I was astonished!"
In 2015, the insurer, Wright USA, had been quietly purchased by Fosun Group, a private company believed to have very close connections with China's leadership.
