FEBA,
Unilaterally by the Secretary of State?
And not as the result of the last round of options, drawn up and approved by the Chiefs of Staff? Withdrawal of Shar has been run as an option several times over the past few years, to my certain knowledge. This time it was selected as being a sensible step. Just ask your 'Very High Up' sources.
And without having determined the ability and willingness of key allies to provide air cover when our ships deployed without SHar (like in the Gulf)?
Do us a favour.
Send Clowns,
The Defence Assumptions do not envisage or require the kind of unilateral national operation you describe, rightly or wrongly. In any case, the presence or lack of SHar would not be as much of a show-stopper as our lack of other key capabilities.