If USAF leave the UK, how would the RAF re-deploy its assets?

http://www.nation.lk/edition/feature-issues/item/25217-after-70-years-of-foreign-troops-bases-should-be-shut-down.html

lots of talks on the UK re-examining its relationship with US forces stationed in the UK. Ranging from stricter controls to outright removal.

in the case the Uk decides to asks its ww2 saviors to go home, how would they redeploy their units to make up for the defensive gaps? It could be a positive for the local defense industry as it might force the UK MOD to purchase more.