[tomohawk]

If Putin uses nukes on Ukraine, do you really think Ukraine, which has access to lots of nuclear material, wouldn't retaliate with a dirty bomb on Red Square and other locations?

Where do you think that would end?

Such a strategic situation would be incredibly unstable. If no retaliation comes, the madman will think he can use the same gambit to take the Baltics and other areas. He's been at this since Chechnya. There's no way he'll stop his aggression and violence unless someone stops him.

The only way to stop this is to effectively deter him from using them in the first place. And the only deterence is to credibly threaten immediate nuclear retaliation.