Lord West of Spithead: “For example, wiping out a whole city is very understandably completely illegal under international law and normally there are certain bases to do these things. Because of this flexible substrategic response, what that in theory allows is use of a nuclear weapon. Rather than your total response to us being wiped out, a single nuclear weapon for a specific reason. Where that is targeted the submarine CO will not know, because none of our warheads at the moment are targeted. They are untargeted. What happens is when the codes come through, if it is a flexible response, he will have a single missile and one warhead that will be targeted somewhere. He will not know what it is and yet in international law as the man who says “go” he will be responsible for this. Do you see what I am getting at? That needs to be clarified, I believe, and it needs to be removed from him. I think that is important.”

Ronnie Cowan: “We have received substantial written evidence on this very topic and it would have been good to take this conversation further.”

Air Chief Marshal Sir Glenn Torpy: “To be absolutely clear, with the targeting we have a very mature process for targeting all of our weapons and it is completely under political control.”

Lord West of Spithead: “Absolutely, but they need to be the ones. It is going to be a politician in the dock, not the submarine CO, that is what I am saying.”

Ronnie Cowan: “It does raise the legality of the person who turns the switch to launch that missile if he does not know where it is targeted.”

Lord West of Spithead: “Absolutely, which is why I believe this needs to be clarified. It does not need to be clarified for the normal deterrence criteria. That is different and that has been done effectively.”

Chair: “But that is impossible to clarify for the inventory officer in the heat of battle or the helicopter commander, wondering whether to”

Lord West of Spithead: “Absolutely. This is a one-off situation, I believe.”

See full text of the debate.