The threat of tariffs is a cheap alternative to actual tariffs in terms of scaring businesses. So don't believe him, or at least trust our government to hit back hard.
Note that he doesn't have the authority to do what he says. His whole tariff scheme right now is framed as national security, but this escalation shit is not going to be forever covered under that excuse. It's the US Congress that has the authority over tariffs and at some point (maybe after the next midterms) this point will be made in the us system.
That is, unless they completely break their democracy first. Goddamn yanks man.