Where nuclear bombs are deployed doesn’t matter a lick offensively and, as a defensive measure, there’s very little to be advantaged by having them in a contested area when retaliation, if it is to come, is better delivered from further away. It does, however, matter quite a bit for purposes of what actions by the other side can be viewed (by each side) as an attempt to eliminate the nuclear deterrent. And that raises the stakes quite a bit.
Of course, the lesson here is simple: if you ever get yourself some atomic bombs never, ever give them up. A nuclear-armed Ukraine would have never had to yield a meter of territory.
