Once we've pulled out of the 'stan there simply won't be enough freight for the current C17s to move let alone an extra one. Discussions I've had have indicated that they're trying to generate a tac role for the ac as there won't be enough of a job left for them & because they anticipate the A400M taking an inordinate length of time before it's capable of anything substantial.
The original plan was for a fleet of A400M & C130J which would have handled pretty much everything we needed to move with the C17s leased for the duration of Herrick & Telic. Now we're stuck with a fleet of oversized jets that will be too expensive to move freight for exercises - the army won't want to pay the costs involved so will move their equipment by cheaper means - and we're scrapping our only Tac & SF capable ac.
Even if the C17 gets the necessary clearances are we really going to insert a small SF team in a monster of an ac that costs circa £50k an hour to operate?