The world doesn't have enough nuclear weapons for "total nuclear annihilation".
To end all humans with the weapons directly? Indeed not.
To break all logistics chains, ending most industrial output, reducing carrying capacity back to the pre-industrial age? That I think is still doable.
Perhaps not, but there's no functional difference to the millions (hundreds of millions even) of victims if you start hitting major population centres.
There's plenty enough to make the second-worst war in human history look like an enjoyable beach vacation by comparison.
To end all humans with the weapons directly? Indeed not.
To break all logistics chains, ending most industrial output, reducing carrying capacity back to the pre-industrial age? That I think is still doable.
Perhaps not, but there's no functional difference to the millions (hundreds of millions even) of victims if you start hitting major population centres.
There's plenty enough to make the second-worst war in human history look like an enjoyable beach vacation by comparison.