I agree in principle that the point of deterrence is to deter nuclear use and not to fight a war using the weapons. However, if faced with first use, deterrence instantly loses its credibility if we demonstrate unwillingness to use the weapons in response. If confronted with a nuclear strike we must respond in kind, or face the likelihood of unilateral escalation by an opponent convinced that deterrence was a bluff.

We should make it clear that nuclear use by Russia will result in a strike on one of its population centres. And we should mean it.