Even if trump really was running his mouth, the calculus of MAD and nuclear warfare demands that every other nuclear armed state takes the threat dead serious.
I suspect the moment his post went out every diplomatic and military side channel was lit up with calls from Russia, China, Pakistan etc telling the US to sit their boy down.
Failing to do so would mean fatally weakening deterrence. The yanks may think themselves safe half a world away, and trump lives in his own invented reality, but no one in the Eurasian continent will stand for this bullshit.
Ouch, owie