kEiThZ
Superstar
The same mentality applies to Russia, the moment one nuke be tactical or otherwise gets used offensively the US will start turning Russia into a crater. Putin would then lose all support and Russia would likely capitulate just like Japan did in WW2.
I wouldn't worry about Russian turning into a crater. That kind of escalation isn't in anybody's interest. What will happen is that the US and UK (most of NATO will be too cowardly to join) will destroy a lot of Russian forces in Ukraine, putting Ukrainian ground forces in a much better position to win quickly. The Russians will also be told that if they escalate outside Ukraine, NATO will go toe-to-toe. And if they nuke Western forces? Well....
But given that we've seeing Russia's own missiles get returned to sender, would they really want to take that chance with their nuclear deterrent, only to have possible follow up from the US? I doubt it. As the video points out, the safety of Russia proper and Putin's regime are the most important thing. Ukraine is not worth a nuclear war to Putin. And definitely not to others in his regime.