Knocked out defenses and secured airspace
Bombing as a sole military tactic has been consistently overrated, since WWII if not before. It's good for two things
- Destroying specific, localized, targets.
- Shaking up the civvies
Broad targets and larger, distributed, or hardened military forces are much harder to shake out. But airplanes, radar, generating capacity, and communications centers are pretty soft targets -- even if hardened there's a lot of stuff you have to leave lying out in the open.
If the US plans to go in with ground troops (infantry or special forces), air support for surveillance and/or strike force, as well as helicoptor transport, is going to be essential. Air force in this context
is effective. There are risks from mobile AA weapons (eg: Stingers, RPGs), but the effectiveness of such weapons is limited, particularly at high altitude and for low, fast, flight (though low, fast, with exposure from above (as in a mountainous region) is not an advisable strategy.
The mountainous regions of Afghanistan have been compared to the Sierra Nevada (there's a training camp off of California Route 108, Sonora Pass, that was covered in the SF Chronicle yesterday). My experience in the Sierra is that fighter overflights just above peak level (given range of 3-5k feet base to peak) gives you advanced warning that
something is coming, but the echos pretty much screw you out of figuring from where, and in what direction. You'd need spotters on major peaks to see and transmit information regarding airstrikes. Without radar, at night, traffic should be relatively safe. IR and low-light scopes excepted.
