Looking at the whole thing from another perspective, the advent of ground-based, precision artillery ranging from MLRS-based GPS missiles, Excalibur artillery shells, GPS-guided 120mm and 81mm mortar rounds, etc coupled with all sorts of tactical UAVs for situational awareness have made the ground forces increasingly less reliant on CAS. These are organic capabilities that can be just as accurate, if not more so, than CAS and will very likely be more responsive when called upon.
re the hilighted bit - actually its the direct opposite.
small units and force effectors are even more acutely aware of what CAS is available to them and its why the role of the JTAC has increased in importance.
In fact army are now attaching soldiers to the JTAC courses so as to give themselves organic experience and to grip up what issues the air force controllers have to deal with. This has been driven by the increasing shift to joint planning constructs (ie multi service in theatre)
Its because there is an increasing shift in platforms and weapons systems becoming nodes and active contributors to SA that these changes are happening - its why you have people in the USMC developing (eg) iPhone apps to takje advantage of 2g, 3g and the 4g spectrum to enhance awareness and appreciation of events in the field.
CAS is about getting the capability anywhere at anytime with the minimum of grief for those who need it, and its why the heavies have made such a significant impact on providing LR support.
CAS is very much bound by the same onion skin layered response model that self defence weapons are part of (eg on a skimmer). All of the CAS weapons detailed above are limited by the fact that they are bound by initial placement and are therefore already constrained by an arc of effect and engagement. Its why there has to be a cash and carry capability for mobile assets (and air provides relative speed and immediacy to get on station within the platforms mobility and placement constraints). "king of the battlefield" weapons are of obvious utility but need to be in range or have final destination update available to provide midcourse correction.
The russians demonstrated the use of tactical battlefield rockets a few years back when they used such a weapon to kill a chechyan leader 80km away based on triangulating signals coming from his mobile/cell/handy phone. Beyond 80km they needed air. - and air needed to be up.
In the 80's the average time for a US air asset to be directed to and engage a target of opportunity was 4hrs - in afghanistan its down to less than 15 minutes assuming that someone is up and running racetracks.
ground based "1st respondent" systems can't fulfill those roles. esp in an unstructured contact model where red team are fighting at range. (eg they're of benefit where ground forces go out every day to rev up red team, but thats a defence centric model where troops are sallying forth from a fixed base of convenience). SF employ a similar model but go out further and for longer, so availablity of air for CAS (be it weapons effect or dropping in support troops from commandos or ranger type units when needed)
