Re: GCHQ is having problems meeting recruitment targets.
"GCHQ is having problems meeting recruitment targets because no one wants to work for a third rate bunch of crypto fascists."
FTFY
GCHQ can't offer the best money or best opportunities out of the intelligence agencies, let alone private sector.
A US based "get out of jail free" card is probably of more use than a UK one.
One presumes also that a highly competent engineer with a deep love of their country would be better off serving the intelligence agencies whilst working at Slurpygooglebook.