GrahamO,
Possibly against my better judgement, I'll take on your arguments, for whatever reason I can't sit back and let them go without reply.
1. the aircraft has yet to fly effectively - its removal is not creating a gap, its failing to fill one which the service appears to be quite happy having for the last decade while ir prevaricates and messes around.
No real problem with the first part (although much of this depends upon your definition of effective), although it has certainly demonstrated much of its capability. However it is fundamentally incorrect to say that we have been without the capability for the last ten years. It is only in the last twelve months that the Nimrod MR2 was removed from service. We have now created a permanent hole in our capability.
2. It was a project based upon reuse of failed bits, adding more unproven bits and generally wasting billions by building upon failure after failure. By scrapping it fully, we prevent the future creation of the next failure, the Nimrod 5 which would the RAF's next late project.
Any evidence to back up this sweeping statement? The reused MR2 fuselages had never failed. As to the adding of "unproven" bits, where possible proven airliner technology was used in MRA4. However you can not build a new military aircraft, years ahead of what any other nation currently operates by using totally proven technology in its sensor and tactical suite. Yes there were issues, but it worked, and improvements were constantly being made. This is no different to any other military project.
3. the RAF should look to itself for the failure. If they had delivered to time and budget and not kept messing around, they would have had their toys by now. Its difficult to justify billions and billions of overspend money being wasted to keep Nimrod going when history suggest that the RAF cannot be trusted to get the project off the ground. Meanwhile soldiers on the ground are dying due to lack of appropriate vehicles. Which do you spend money on - vehicles which will clearly save lives, or spend it on more delays on Nimrod. Its a no brainer.
I'll happily concede that there have been major issues within this project, and that I don't know enough about what went on to discuss it. It is interesting though that no-one in government/MoD has yet countered the argument that these aircraft were paid for, and therefore the savings, if any, are minimal. WRT your point about the vehicles, I don't have a problem with that requirement, but it sums up the entire SDSR. We have traded our overall military capability in order to support this particular conflict. Whilst this may be fine in the short time, the issue is that capabilities such as this can not be resurrected in short order in terms of either hardware or trained personnel.
Whilst requirement is a subjective argument I still can not get my head around that we should get rid of the only asset that could investigate anything in our vast maritime area of responsibility in a matter of minutes/hours.