I think we should start thinking of armed security officers at these barriers as they already do in other European Airports.
Heathrow is plenty of weak airside access points too... and if somebody wants to break through, even with a van, they can easily do it and nobody has got weapon to dissuade them!
A standard security unarmed guy positioned there is insufficient nowadays and does not represent a deterrent at all!
We should follow what they do in other European airports: each airport access should have a guy with a machine gun there.
We should also position (urgently) armed officers at each terminal entrance as it is too easy now to enter a Terminal and blow it up.
In other airports abroad each Terminal entrance is guarded by a heavily armed officer who can also ask for tickets and check identities if needed. This, at present, would make sense.