Heh, I got a laugh out of that. :D

It is absurd to think an other power would let you operate on its soil OR its owned equipement, without having possibility to control the system.

Mr Ainslie: There are two sides of the software system. There is the shore-based bit of the software and the submarine end. At the submarine end it is clearly entirely American. At the shore-based end some of the key components come from the United States. In some of the American contracts is an insight into the process. The Americans produce software models for their own Trident system. Those models include information which is classified to such a level that it cannot be given to Britain, so those bits are then taken out and that reduced version is given to Britain as the software models. These are then assessed in the software facility that Britain has to see if they will work and there are other things added. My point is that, although there is access to the process, because the gaps are there, for reasons of security, I do not believe they can then assess it to the extent of being certain that that software has not been crippled in such a way that would reduce restricted use in particular circumstances. The background to this is that the software is extremely complex. In order to get the accuracy that Trident requires, there is a very large software infrastructure in America that supports this. We have not duplicated that. You have talked about what we build and what we do not build. We have some ability to check the software; we have not duplicated it. We do not have our own experts who can do all these tasks.

Q20 Linda Gilroy: Is the point you are making that somewhere in that software is the capacity to stop in fairly short order the ability of the United Kingdom to target and operate missiles?

Mr Ainslie: There is a number of ways, if the intention was there, that from the United States end they could do it. The system can almost certainly distinguish between a plan which is produced only within the British system or a plan which is produced within the American system. There are all sorts of levels going in, so they can probably distinguish between those two.

Q21 Linda Gilroy: Those are assertions and statements. Can you source those for us in some further note?

Mr Ainslie: Yes. I have written something on this recently, so I can give you a copy of that.

Q22 Chairman: You say the potential exists for that to happen rather than your having any evidence.

Mr Ainslie: Precisely. It is a potential vulnerability. Clearly, at levels of classification involved in this it would be very difficult to verify.

Q23 Mr Hancock: Have you read the previous evidence we have had at the Committee?

Mr Ainslie: Yes.

Mr Hancock: We were assured that the guidance and targeting mechanisms were wholly British and were unstoppable if a British Prime Minister gave authorisation for their use - their independent use. When the questions were put to the panel on that day, a number of members seriously questioned whether that was an accurate interpretation. The answer came back that, irrefutably, there was no possibility whatsoever, once the command to fire a missile from a British submarine was given, that firing could in any way be impeded by a source outside of the summary or outside of the chain of command in the United Kingdom. I am a little surprised, to say the least, that you believe there is evidence - not just the possibility but the evidence - to suggest that is a possibility. We were given a cast-iron assurance. It was the only thing that determined whether or not we had an independent deterrent.

Chairman: I think you said there was not evidence that it was possible but that it was a potential.

Q24 Mr Hancock: We were told it was not possible. That is different from potential. When somebody says, sitting where you are, that it is impossible to do that, then we have to either prove them wrong by saying this is how it can be done or we have to accept that. I am thinking that there is a real

From that extract all I took out of it was that unless America gives us accurate weather forcasts (why can't we do this), our missiles will be less accurate.  But given that we are talking about nuclear warheads, and that the majority of the missiles flight will be above the weather - who cares?

As to whether our software works or not full stop - I suggest we pick a random missile, remove the warheads, let the world know, and fire it off into the South Pole.  If it fizzles rather than flies we know it doesn't work.

In such an instance I would suggest taking our British designed and produced warheads, and sticking them in British designed and produced dumb-bombs, under Tornados, until we can come up with a better idea.

But how are the Americans to access the software to alter it?

Exactly - so it either works - or it doesn't.

Once the coded message from the PM arrives on the boat, it's fireworks all round.