FOD - one could (and should) infer that he is talking about the Libyan scenario (but to whom are we providing CAS), but the tone of the letter is ambiguous, hence my throwaway comment.
I suspect the editing, but for the reasons I've adduced elsewhere, I am not entirely confident that a spot of smoke & mirrors might not have crept in.
As for the point being self-evident, again, agreed: but he fails to note in his wider contentions (not just this letter) that the same applies for carrier based air providing CAS in Afghanistan.
As for the inability to respond swiftly, Rector16 has illustrated why the Wardian narrative of Harriers holding deck alert leaping off to the rescue while the land-based air plods towards the scene of the bother is wrong; the basic notion that having air on hand promptly is a good thing is undeniable, but the letter suggests that the issue of response times is a matter of black and white, when that isn't quite the case.