In the ICAO documents the aim of ATC is to "prevent collisions between aircraft".
A nation's airspace is (should be) then designed, according to local conditions, to enable controllers to fulfill that requirement.
Why then does ICAO countenance airspace that does not fulfil that requirement? Why is ICAO happy for ATC to only prevent collisions between some aircraft, but not all?
They are, however, hobbled in this country, by lack of surveillance
You can have ATC without surveillance, it's just inefficient. If, however, ICAO doesn't mandate it anyway "to prevent collisions between aircraft", what good is their aim or even their charter? Why all the emphasis on being ICAO compliant, when they are toothless tigers.
Get a system that works for us, and if it isn't ICAO compliant, who gives a sh*t.