In my world: Fighter aircraft are PART of the air defence. The russian concept of using primarely SAM's and point-defence interceptors guided by a ground controller with absolute authority - simply isn't flexible enough. A static missile belt will be torn apart - its a question of time. A mobile missile belt does not provide sufficient cover, as the integration problem between the different missile systems is enormeous. reliance on solely ground based radars is to vulnerable on its own against Wild Weasels for instance. To some extend the Soviets were right in creating a special arm: AIR DEFENCE on line with army and navy and air force. But in my view they didn't use this independence to promote the flexibility that is the hallmark of a good air defence system. As You might understand: I'm not AGAINST SAM's, but all for a balanced air defence.

Directed Energy Weapons (aka LASERS, microwave weapons) may be the only thing that really calls in to question the viability of airpower. An ABL derivative may one day be able to target and near-instantanously destroy groups of aircraft from 200 miles away.

...Any fixed target can be destriyed if enough efford is put in. Any country relying on fixed defesive measures will find that an agressor can focus it's attacking capabilities on one spot overwhelming the defence sam's/radar/THEL whatever. Than a corridor can be formed, the main hubs of (defensive) infrastructure taken out, and there after it's all down hill. Most countries have a top down defensive system, often layered but still top down intergrated. Take out the centre (no nessesarily geographical) and you win. Only a horizontal organised independantly operating aior defense system will continue to remain some sort of thread E.g. A system containing sam's with a kill range of 50 km or so who can "talk" to each other wireless without it being able to be jammed. This system can relocate, redistribute itself again after a coridor has be formed, closing the gap. The decission to do so ( the reforming part) can not be centralized, but at the very lowest level, possible through good training

DEWs will be restricted to LOS system - never BLOS. Physics 101. Concentrated light and the atmosphere do not mix well. So, no, you will not find ground based systems with ranges pushing 200 miles (or half that). As a subnote, hence the ABL program. Atmospheres alot thinner at 32,000 feet. Its not air power thats threatened with obsolesence, its ground-based air defenses. As aircraft get higher and faster, the range with which you can drop munitions (with and without independent propulsion systems) will increase conversely, without ANY additional ordnance development. Ground systems, on the other hand, are restricted by the fact that they must supply their own propellant. Instead of having the advantage of gliding, and using the force of gravity, they must climb, beating that same force. The launch platform is typically static AT LAUNCH (system itself may be mobile, of course), while an airborne launch platform is moving at many hundreds of miles an hour. Look at the JDAM and JSOW - these are dumb bombs with bolt-on glide kits that have 10-30+ mile ranges. Such things simply aren't possible on the ground..