There are statements on this web site saying that we can no longer afford the do Iraq/Afghanistan - therefore we don't need a carrier. This is a flawed (illogical) argument. The logic is that to avoid the costs of another Afg we need to avoid 'invading' countries when we 'help them out'. So, tanking the GRs and then letting them stay there immediately puts us into the invasion category (long drawn-out conflict with problems 'getting out'). Carriers enable us to avoid this situation.
If the scope of the conflict is merely to turn up and destory some targets or loiter in the area with a big stick then carriers achieve that aim perfectly.
Yet for a conflict of the scope of Iraq/Afghanistan as soon as ground forces are commited the invasion line has been crossed and having some carrier based aviation that can be withdrawn more quickly is irrelevant. Furthermore, given the number of ground forces required to clear and hold ground for an extended period of time and the demands those forces have for resupply it would seem that some form of local land based aviation is a requirement.
The 'niche' argument for and against carrier aviation is misleading - surely it is about scenarios?
In the scenario where there are no friendly countries in the region that can support land based aviation or where we don't want to commit for an extended period or in the Falklands scenario then a carrier is the only choice.
In the scenario where there are friendly countries in the region or where we are going to be in the region for an extended period of time then land based air power would seem to be a more effective approach.
Also, taking the case of Afghanistan, given the ~500-mile round trip from the Indian ocean to the southern border of Afghanistan, the argument for purely carrier based aviation can only extend to fast-air, not to helicoptor resupply and certainly not casualty evacuation - that must be local.
So from a scenario perspective does the UK want to and can it afford to build and maintain a force that can cover all expeditionary scenarios in addition to all of the other defence scenarios?