2+2=?
FB let me try and give you a more measured answer.
If you took the No Fly Zone as a literal concept (and I accept that you were) then Haart's views deserve merit; however, such absolutes rarely exist other than in open warfare - something that this is not.
Enforcing a No Fly Zone is a very complex business and the simple moniker NFZ does not do that complexity justice (I doubt if even many politicians understand that). The nub of the problem is that you cannot enforce one on the basis that "it flies it dies". What about air ambulances, defectors, other innocent humanitarian or commercial flights. In order to enforce in a complex environment you need presence not just the threat of violence. A quick glance in a Flight Information Handbook will show that there are a variety of methods you can use to dissuade enemy action or identify peaceful intent. In many ways an air presence saves the politicians from the unintended consequences of their rhetoric. A No Fly Zone may be a No Drive Zone or it may be a Some Fly Zone - you need options to cope with all of these simultaneously. Also, that presence provides the opportunity for hard intelligence.
The other major factor is that the physical presence of air over a country sends wider messages than just to the leadership - deterrence and coercion is a complex business but contrails and jet noise above you can provide a very visible sign of intent to both sides of a dispute. Now if we could just find a cheap contrail and jet noise machine!
I did not duck the question, I assumed knowledge - for that I apologise.
Capt P