Is TikTok a national security threat – or is the ban a smokescreen for superpower rivalry?

Washington looks happy for the video app to harvest users' data - as long as China does not reap the rewards

If the Chinese-owned TikTok is deemed definitively by the US to be a national security threat, it is hard to see how the UK or other western countries could conclude differently.

But the fact that Donald Trump has walked into the White House talking of a reprieve for the video-sharing network, which restored its service in the US after going dark for a day, suggests something simpler is at work - Trumpian geopolitics.