Current Liberal Democrat policy is that we reduce our fleet of nuclear missile submarines from four to three – but reducing the cost of our nuclear programme by less than a quarter. Most of the time we intend to have a nuclear missile submarine at sea but not armed with nuclear missiles. However at times of international tension we would sortie a submarine armed with nuclear weapons.
Trident and its successors are designed to penetrate sophisticated air defence systems such as those developed by Russia. I can think of no occasion when it would be rational for the United Kingdom to launch missiles at such a foe without the support of other major powers. No scenario in which an independent launch against such a major foe would be a sensible option has been put forward in the current debate.
Delegates to conference who think the three submarine strategy is a sensible use of £100bn can keep this policy by voting down the motion before conference.