Nice to have but do we really "need" a separate RAF?
I'm sure the default position of most on this site is "keep the RAF come hell or high water" but do we actually need a third force? This is a different question to "do we need the war fighting capabilities that the RAF presently provides"; which of course we do. As far as I can see all of the capabilities presently provided by the RAF are fully capable of and are provided by the Navy, Army or Marine Corps organisations of a number of our NATO allies.
If such a change should ever come about it will be because the bean counters have decided large sums of money can be saved. After all this present government is looking at ways to merge much of the police and fire service as the Home Office has decided its a money saving wheeze. So if they're prepared to do that why not divvy out the work of the RAF to the other two organisations that fly military aircraft? Regardless, of history or tradition if it will save money I'm sure someone in HM Treasury will be looking seriously at it