Not knowing in which country I live in, doesn't mean you can't threaten me. As long as I can understand your language, I can interpret threats. And what the president can do and can't do, I already know that. I also know what consequences he might face if he does anything stupid like that.
Something like "if I ever find you, I'll kill you!" is also a threat, and one that strongly implies not knowing where the victim is, right?
And yeah, your quotes strongly implied that if I didn't keep my big mouth shut about the U.S. I might get blown of the Earth. Considering the weapons the U.S. has at its disposal, you don't need to know where I am to do that to me, but that is not even relevant.