Honestly, if throwing nukes in Europe, including nuclear fallout over NATO states, is not the red line, then there isn't any. If you allow Putin to throw nukes and answer with more economic sanctions, then the West is a complete joke.
Ukraine never joined NATO. Ukraine was never even given a membership action plan.
> and the west didn't care about his line drawing.
Neither did Putin; the moving red lines were about pretext, not reasoning.