Certainly the US government could make a logical case for that, couldn't they? If China controls the algorithms of TikTok, they can manipulate what messages or content gets amplified or suppressed, right? And that would present a risk for meddling or tampering in domestic politics by a foreign government, right?

I have no idea what legal mechanisms the US govt has to pursue something like this, nor am I a user of TikTok, so I may be speaking from a point of ignorance here.