In wartime this would have been dealt with in about three minutes flat. In peacetime this is a REAL challenge. There is no way you can contemplate shooting the thing down as the risk of a miss or even a hit resulting in the round killing a 4 year old girl playing in her back garden is far FAR too great. As to 'dominating the local area" with a rock squadron, what on earth would be the point? This thing could be being controlled from anywhere on the planet.
Retired BA/By
Not sure just how CAS can effect this at all. Shorad went to the Army years ago, you cannot even consider shooting it down with a fast jet, and even a sniper from a helicopter has the unacceptable risk attached as described above.
I should think that electronic jamming also has a problem of taking out a lot of unintended capability locally.
A drone over Gatwick is a very different proposition from something similar crossing into Israel.