The threat wasn’t to attack. It was more of a warning, saying that if NATO was to step onto Russian soil he would use them.
Nuclear weapons are basically a defensive weapon. You never aim to use them but you have them as a deterrent. No country wants to mess with it or test whether a nuclear nation would use it
To do so is suicide, both to call their bluff or to use the weapons. So you get into a state where militarily no one can do anything (except wage a war in a country that doesn’t have nuclear weapons).
That’s kinda the purpose of nuclear weaponry. To use then it’s basically game over for everyone everywhere.
you get into a state where militarily no one can do anything (except wage a war in a country that doesn’t have nuclear weapons)
ok, I got it. Give every country nuclear weapons and then there is nowhere to wage war.
The proviso of this is that all the countries involved are led by sane, (reasonably) rational leaders. It also breaks down if they get into the hands of non-governmental forces. If they get into the hands of someone willing to act irrationality, a lot of people will be very screwed.
Interestingly, Ukraine was once a nuclear power. They had a significant chunk of the USSR’s arsenal. They decommissioned them, due to safety concerns. Part of that deal was protection from invasion (both from Russia and NATO). I suspect they now regret giving up their nukes.
