Another point:
The UK has only just recently shown that it won't act unilaterally against a foe which could be described as 'shoddy' at best. We would rather stand behind the big boys and get involved once the adversary was down and out.
So it begs the question, if we've not got the balls to attack even Libya on our tod (or until the rats in parliament get approval from the 'tards), when will we ever need the capabilities offered by F35 to attack a country with half decent kit???
Just give the spams a call and ask for some of their 'unique capabilities', they don't even need an excuse to go to war, they love killing and maiming and they're very good at it too !!!!
If you require deep strike in the future, get FOAS-CALCM off the back burner, **** the spams.