UK's Nuclear Deterrent

My hon. Friend is making a powerful speech on the cost, and he is absolutely right of course that we must keep costs under review and make sure that BAE and others deliver on time and on budget, but on the question of Cruise missiles, is there not a danger that were we to nuclear-arm Cruise missiles, any Cruise attack would have to be seen as a nuclear attack and therefore to be responded to in kind? Is there not a danger that Cruise missiles would up the ante, rather than lower it?