On 29 December 2006, the Archbishop of Canterbury accepted an invitation to guest edit an edition of Radio 4's Today programme. Dr Williams asked the programme’s producers to look into a number of issues, including the morality of possessing Trident missiles.

Commenting on whether even the threat of using nuclear weapons can ever be considered morally acceptable, Dr Williams argued that:

"I've never been convinced that the threat of using a nuclear weapon is totally different from the actual use - you imagine what would be involved in the mass slaughter of the innocent, you plan for what would be involved in the mass slaughter of the innocent: I think there are moral problems with that, I really do, and I think it does something to your own imagination to go down that route of planning and thinking of it."

"My judgement has always been that the nuclear deterrent - the threat of mass slaughter of the innocent by a nuclear weapon is not morally acceptable."