This foreign policy article argues that Israel’s incursions into Syria show that Syria’s air defenses are little to worry about (and hence a no-fly zone should be set up).
But among the likely weapons used by the IAF against targets in Damascus are the above ‘Popeye’ (or Spice) missiles, which can be fired accurately at extremely long range (e.g. reaching Damascus from Lebanese airspace).
This renders the foreign policy piece completely unfounded. It is doubtful Israel sent fighter jets into Syria (let alone over Damascus) in either of the two recent attacks. And at any rate a quick incursion is not comparable to the routine flights necessary for a no-fly zone (where even a lone gunman with a surface-to-air missile can score a lucky hit).