Theresa May says that she would definitely press the button to launch a Trident missile and explode a nuclear bomb.

Jeremy Corbyn says that he definitely wouldn’t.

Some thoughts. The context of this discussion is the the theory of MAD, or mutually assured destruction.

In order for MAD to be effective, the opponents have to be willing – and committed – to launch their weapons if the trigger condition (as defined) is met. Put another way, there will always be a situation where one of the opponents can reasonably expect that, if A launches an attack, B will respond with a nuclear strike.

Conversely, MAD doesn’t work if various conditions occur. These include the following.

MAD will not work if one of the opponents has foresworn the use of nuclear weapons, ever. There is no mutual threat.

MAD will also not work if one or other of the opponents does not have free and unfettered use of a nuclear weapon.

In the context of the UK and its Trident weapon, MAD is, in view of the above, not operative, either actually under May or potentially under Corbyn.

Under May, although she is willing to wreak nuclear destruction, she is not a free agent in relation to the use of the Trident missile system, as she needs a ‘second key’ from the USA in order to launch a missile. Unless the USA have previously let it be known to the other side that she is authorised by them to act, her threats are empty.

Under a hypothetical Corbyn government, there is no risk of a nuclear strike by the UK either, as Corbyn has foresworn the use of nuclear weapons.

The question therefore arises that, given that, under neither the actual or the potential regime, is a nuclear threat from the UK credible, why would the not inconsiderable cost of renewing the Trident ‘deterrent’ be justified?

Note that this conclusion may be reached without any consideration whether the actors in any potential nuclear exchange are not identified, or, arguably, identifiable.

Hugh Bryant

19th July 2016