At what point does Putin attempting to extort concessions by disrupting the world's food supply, like some kind of Bond villain*, become enough of an issue that more sensible minds decide it's gone on long enough, and that it is time to demand he take what's of his army and go home, or sit back and watch your war machine be utterly destroyed before breakfast tomorrow. And if he wants to rattle the atomic sabre, remind him that while he may have more on paper, ours are more powerful, more accurate, and most of all, well maintained. Then state in plain terms, use nukes and we'll hit Russia so hard it may tilt the Earth itself on its axis, making what's left of them the new North Pole.
Sure, it's a long winded fantasy that'll never happen, but it felt good it get it out.
*Been a while since anyone evoked such a claim, but dang, what else would you call him at this point?